1390281961 has 4 divisors (see below), whose sum is σ = 1392385924. Its totient is φ = 1388178000.

The previous prime is 1390281877. The next prime is 1390281973. The reversal of 1390281961 is 1691820931.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1691820931 = 1087 ⋅1556413.

It can be written as a sum of positive squares in 2 ways, for example, as 380250000 + 1010031961 = 19500^2 + 31781^2 .

It is a cyclic number.

It is not a de Polignac number, because 1390281961 - 2¹³ = 1390273769 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1390291961) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1050990 + ... + 1052311.

It is an arithmetic number, because the mean of its divisors is an integer number (348096481).

Almost surely, 2^1390281961 is an apocalyptic number.

It is an amenable number.

1390281961 is a deficient number, since it is larger than the sum of its proper divisors (2103963).

1390281961 is an equidigital number, since it uses as much as digits as its factorization.

1390281961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2103962.

The product of its (nonzero) digits is 23328, while the sum is 40.

The square root of 1390281961 is about 37286.4849643943. The cubic root of 1390281961 is about 1116.0944861720.

The spelling of 1390281961 in words is "one billion, three hundred ninety million, two hundred eighty-one thousand, nine hundred sixty-one".