1521257664 has 56 divisors (see below), whose sum is σ = 4133797168. Its totient is φ = 493378560.

The previous prime is 1521257663. The next prime is 1521257671. The reversal of 1521257664 is 4667521251.

It is not an unprimeable number, because it can be changed into a prime (1521257663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 99967 + ... + 114174.

Almost surely, 2^1521257664 is an apocalyptic number.

It is an amenable number.

1521257664 is an abundant number, since it is smaller than the sum of its proper divisors (2612539504).

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

1521257664 is a wasteful number, since it uses less digits than its factorization.

1521257664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 214193 (or 214183 counting only the distinct ones).

The product of its digits is 100800, while the sum is 39.

The square root of 1521257664 is about 39003.3032447253. The cubic root of 1521257664 is about 1150.0964415654.

The spelling of 1521257664 in words is "one billion, five hundred twenty-one million, two hundred fifty-seven thousand, six hundred sixty-four".