664172541 has 80 divisors (see below), whose sum is σ = 1116111744. Its totient is φ = 391412736.

The previous prime is 664172501. The next prime is 664172549. The reversal of 664172541 is 145271466.

664172541 is a `hidden beast` number, since 6 + 6 + 41 + 72 + 541 = 666.

It is not a de Polignac number, because 664172541 - 2¹⁰ = 664171517 is a prime.

It is a super-2 number, since 2×664172541² = 882250328436793362, which contains 22 as substring.

It is a hoax number, since the sum of its digits (36) 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 = 664172496 and 664172505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664172549) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 2121801 + ... + 2122113.

Almost surely, 2^664172541 is an apocalyptic number.

It is an amenable number.

664172541 is a deficient number, since it is larger than the sum of its proper divisors (451939203).

664172541 is a wasteful number, since it uses less digits than its factorization.

664172541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 432 (or 423 counting only the distinct ones).

The product of its digits is 40320, while the sum is 36.

The square root of 664172541 is about 25771.5451806833. The cubic root of 664172541 is about 872.4896936137.

The spelling of 664172541 in words is "six hundred sixty-four million, one hundred seventy-two thousand, five hundred forty-one".