1215644764 has 24 divisors (see below), whose sum is σ = 2158990848. Its totient is φ = 598809600.

The previous prime is 1215644713. The next prime is 1215644797. The reversal of 1215644764 is 4674465121.

It is a congruent number.

It is an unprimeable number.

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, 334284 + ... + 337900.

It is an arithmetic number, because the mean of its divisors is an integer number (89957952).

Almost surely, 2^1215644764 is an apocalyptic number.

It is an amenable number.

1215644764 is a deficient number, since it is larger than the sum of its proper divisors (943346084).

1215644764 is a wasteful number, since it uses less digits than its factorization.

1215644764 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4845 (or 4843 counting only the distinct ones).

The product of its digits is 161280, while the sum is 40.

The square root of 1215644764 is about 34866.0976307932. The cubic root of 1215644764 is about 1067.2567116106.

The spelling of 1215644764 in words is "one billion, two hundred fifteen million, six hundred forty-four thousand, seven hundred sixty-four".