1664540523 has 24 divisors (see below), whose sum is σ = 2495374336. Its totient is φ = 1108809000.

The previous prime is 1664540513. The next prime is 1664540539. The reversal of 1664540523 is 3250454661.

1664540523 is a `hidden beast` number, since 1 + 6 + 64 + 540 + 52 + 3 = 666.

It is not a de Polignac number, because 1664540523 - 2⁵ = 1664540491 is a prime.

It is a super-2 number, since 2×1664540523² = 5541390305418227058, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1664540513) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 472338 + ... + 475848.

Almost surely, 2^1664540523 is an apocalyptic number.

1664540523 is a deficient number, since it is larger than the sum of its proper divisors (830833813).

1664540523 is an equidigital number, since it uses as much as digits as its factorization.

1664540523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5477 (or 5465 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 36.

The square root of 1664540523 is about 40798.7809009044. The cubic root of 1664540523 is about 1185.1267225479.

The spelling of 1664540523 in words is "one billion, six hundred sixty-four million, five hundred forty thousand, five hundred twenty-three".