15640994 has 8 divisors (see below), whose sum is σ = 23480400. Its totient is φ = 7814196.

The previous prime is 15640987. The next prime is 15641011. The reversal of 15640994 is 49904651.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1097 + ... + 5699.

It is an arithmetic number, because the mean of its divisors is an integer number (2935050).

Almost surely, 2^15640994 is an apocalyptic number.

15640994 is a deficient number, since it is larger than the sum of its proper divisors (7839406).

15640994 is a wasteful number, since it uses less digits than its factorization.

15640994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6304.

The product of its (nonzero) digits is 38880, while the sum is 38.

The square root of 15640994 is about 3954.8696565121. The cubic root of 15640994 is about 250.0852722446.

The spelling of 15640994 in words is "fifteen million, six hundred forty thousand, nine hundred ninety-four".