402149921 has 2 divisors, whose sum is σ = 402149922. Its totient is φ = 402149920.

The previous prime is 402149911. The next prime is 402149947. The reversal of 402149921 is 129941204.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 340919296 + 61230625 = 18464^2 + 7825^2 .

It is a cyclic number.

It is not a de Polignac number, because 402149921 - 2²² = 397955617 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (402149911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 201074960 + 201074961.

It is an arithmetic number, because the mean of its divisors is an integer number (201074961).

Almost surely, 2^402149921 is an apocalyptic number.

It is an amenable number.

402149921 is a deficient number, since it is larger than the sum of its proper divisors (1).

402149921 is an equidigital number, since it uses as much as digits as its factorization.

402149921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 402149921 is about 20053.6759971832. The cubic root of 402149921 is about 738.1240045199.

The spelling of 402149921 in words is "four hundred two million, one hundred forty-nine thousand, nine hundred twenty-one".