15664431 has 8 divisors (see below), whose sum is σ = 21450544. Its totient is φ = 10160640.

The previous prime is 15664423. The next prime is 15664457. The reversal of 15664431 is 13446651.

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

It is not a de Polignac number, because 15664431 - 2³ = 15664423 is a prime.

It is a super-2 number, since 2×15664431² = 490748797107522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15664421) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 70450 + ... + 70671.

It is an arithmetic number, because the mean of its divisors is an integer number (2681318).

Almost surely, 2^15664431 is an apocalyptic number.

15664431 is a deficient number, since it is larger than the sum of its proper divisors (5786113).

15664431 is a wasteful number, since it uses less digits than its factorization.

15664431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 141161.

The product of its digits is 8640, while the sum is 30.

The square root of 15664431 is about 3957.8316032899. The cubic root of 15664431 is about 250.2101220121.

The spelling of 15664431 in words is "fifteen million, six hundred sixty-four thousand, four hundred thirty-one".