664156236 has 12 divisors (see below), whose sum is σ = 1549697912. Its totient is φ = 221385408.

The previous prime is 664156219. The next prime is 664156237. The reversal of 664156236 is 632651466.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×664156236² = 882207011635375392, which contains 22 as substring.

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 664156194 and 664156203.

It is not an unprimeable number, because it can be changed into a prime (664156237) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27673165 + ... + 27673188.

Almost surely, 2^664156236 is an apocalyptic number.

It is an amenable number.

664156236 is an abundant number, since it is smaller than the sum of its proper divisors (885541676).

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

664156236 is a wasteful number, since it uses less digits than its factorization.

664156236 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55346360 (or 55346358 counting only the distinct ones).

The product of its digits is 155520, while the sum is 39.

The square root of 664156236 is about 25771.2288414813. The cubic root of 664156236 is about 872.4825538721.

The spelling of 664156236 in words is "six hundred sixty-four million, one hundred fifty-six thousand, two hundred thirty-six".