1391961481 has 3 divisors (see below), whose sum is σ = 1391998791. Its totient is φ = 1391924172.

The previous prime is 1391961469. The next prime is 1391961491. The reversal of 1391961481 is 1841691931.

It is a happy number.

The square root of 1391961481 is 37309.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 679071481 + 712890000 = 26059^2 + 26700^2 .

It is not a de Polignac number, because 1391961481 - 2¹¹ = 1391959433 is a prime.

It is a super-2 number, since 2×1391961481² = 3875113529175426722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1391961491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 18655 + ... + 55963.

It is an arithmetic number, because the mean of its divisors is an integer number (463999597).

Almost surely, 2^1391961481 is an apocalyptic number.

1391961481 is the 37309-th square number.

1391961481 is the 18655-th centered octagonal number.

It is an amenable number.

1391961481 is a deficient number, since it is larger than the sum of its proper divisors (37310).

1391961481 is an frugal number, since it uses more digits than its factorization.

1391961481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74618 (or 37309 counting only the distinct ones).

The product of its digits is 46656, while the sum is 43.

The cubic root of 1391961481 is about 1116.5437352556.

Multiplying 1391961481 by its product of digits (46656), we get a square (64943354857536 = 8058744²).

The spelling of 1391961481 in words is "one billion, three hundred ninety-one million, nine hundred sixty-one thousand, four hundred eighty-one".