1921481 has 2 divisors, whose sum is σ = 1921482. Its totient is φ = 1921480.

The previous prime is 1921477. The next prime is 1921483. The reversal of 1921481 is 1841291.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1585081 + 336400 = 1259^2 + 580^2 .

It is an emirp because it is prime and its reverse (1841291) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1921481 - 2² = 1921477 is a prime.

It is a super-2 number, since 2×1921481² = 7384178466722, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 1921483, it forms a pair of twin primes.

It is a Chen prime.

It is an Ulam number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1921481.

It is not a weakly prime, because it can be changed into another prime (1921483) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 960740 + 960741.

It is an arithmetic number, because the mean of its divisors is an integer number (960741).

2^1921481 is an apocalyptic number.

It is an amenable number.

1921481 is a deficient number, since it is larger than the sum of its proper divisors (1).

1921481 is an equidigital number, since it uses as much as digits as its factorization.

1921481 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 576, while the sum is 26.

The square root of 1921481 is about 1386.1749528829. The cubic root of 1921481 is about 124.3212490481.

The spelling of 1921481 in words is "one million, nine hundred twenty-one thousand, four hundred eighty-one".