1521247664 has 20 divisors (see below), whose sum is σ = 3049053360. Its totient is φ = 734395200.

The previous prime is 1521247661. The next prime is 1521247691. The reversal of 1521247664 is 4667421251.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (1521247661) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1638812 + ... + 1639739.

It is an arithmetic number, because the mean of its divisors is an integer number (152452668).

Almost surely, 2^1521247664 is an apocalyptic number.

It is an amenable number.

1521247664 is an abundant number, since it is smaller than the sum of its proper divisors (1527805696).

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

1521247664 is a wasteful number, since it uses less digits than its factorization.

1521247664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3278588 (or 3278582 counting only the distinct ones).

The product of its digits is 80640, while the sum is 38.

The square root of 1521247664 is about 39003.1750502443. The cubic root of 1521247664 is about 1150.0939215037.

The spelling of 1521247664 in words is "one billion, five hundred twenty-one million, two hundred forty-seven thousand, six hundred sixty-four".