1664688503520 has 240 divisors, whose sum is σ = 6714243996768. Its totient is φ = 380500208640.

The previous prime is 1664688503501. The next prime is 1664688503561. The reversal of 1664688503520 is 253058864661.

1664688503520 is a `hidden beast` number, since 1 + 6 + 6 + 4 + 6 + 88 + 503 + 52 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

It is a hoax number, since the sum of its digits (54) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 9084151 + ... + 9265590.

Almost surely, 2^{1664688503520} is an apocalyptic number.

1664688503520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1664688503520 is an abundant number, since it is smaller than the sum of its proper divisors (5049555493248).

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

1664688503520 is a wasteful number, since it uses less digits than its factorization.

1664688503520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18349775 (or 18349758 counting only the distinct ones).

The product of its (nonzero) digits is 8294400, while the sum is 54.

The spelling of 1664688503520 in words is "one trillion, six hundred sixty-four billion, six hundred eighty-eight million, five hundred three thousand, five hundred twenty".