1664137525 has 12 divisors (see below), whose sum is σ = 2083568032. Its totient is φ = 1318382640.

The previous prime is 1664137511. The next prime is 1664137543. The reversal of 1664137525 is 5257314661.

It is not a de Polignac number, because 1664137525 - 2²⁵ = 1630583093 is a prime.

It is a super-2 number, since 2×1664137525² = 5538707404226251250, which contains 22 as substring.

It is a hoax number, since the sum of its digits (40) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 320559 + ... + 325708.

Almost surely, 2^1664137525 is an apocalyptic number.

It is an amenable number.

1664137525 is a deficient number, since it is larger than the sum of its proper divisors (419430507).

1664137525 is a wasteful number, since it uses less digits than its factorization.

1664137525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 646380 (or 646375 counting only the distinct ones).

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

The square root of 1664137525 is about 40793.8417533823. The cubic root of 1664137525 is about 1185.0310720784.

The spelling of 1664137525 in words is "one billion, six hundred sixty-four million, one hundred thirty-seven thousand, five hundred twenty-five".