402139915 has 4 divisors (see below), whose sum is σ = 482567904. Its totient is φ = 321711928.

The previous prime is 402139909. The next prime is 402139937. The reversal of 402139915 is 519931204.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-402139915 is a prime.

It is a super-2 number, since 2×402139915² = 323433022472414450, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40213987 + ... + 40213996.

It is an arithmetic number, because the mean of its divisors is an integer number (120641976).

Almost surely, 2^402139915 is an apocalyptic number.

402139915 is a deficient number, since it is larger than the sum of its proper divisors (80427989).

402139915 is an equidigital number, since it uses as much as digits as its factorization.

402139915 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80427988.

The product of its (nonzero) digits is 9720, while the sum is 34.

The square root of 402139915 is about 20053.4265151869. The cubic root of 402139915 is about 738.1178826487.

The spelling of 402139915 in words is "four hundred two million, one hundred thirty-nine thousand, nine hundred fifteen".