15765664 has 48 divisors (see below), whose sum is σ = 33398568. Its totient is φ = 7299072.

The previous prime is 15765661. The next prime is 15765667. The reversal of 15765664 is 46656751.

It is an interprime number because it is at equal distance from previous prime (15765661) and next prime (15765667).

It can be written as a sum of positive squares in 4 ways, for example, as 15523600 + 242064 = 3940^2 + 492^2 .

It is a super-2 number, since 2×15765664² = 497112322721792, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (15765661) 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, 39514 + ... + 39910.

Almost surely, 2^15765664 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 15765664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16699284).

15765664 is an abundant number, since it is smaller than the sum of its proper divisors (17632904).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

15765664 is a wasteful number, since it uses less digits than its factorization.

15765664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 497 (or 489 counting only the distinct ones).

The product of its digits is 151200, while the sum is 40.

The square root of 15765664 is about 3970.5999546668. The cubic root of 15765664 is about 250.7479679441.

The spelling of 15765664 in words is "fifteen million, seven hundred sixty-five thousand, six hundred sixty-four".