28731997764 has 36 divisors (see below), whose sum is σ = 72642029824. Its totient is φ = 9575496432.

The previous prime is 28731997741. The next prime is 28731997769. The reversal of 28731997764 is 46779913782.

It is a tau number, because it is divible by the number of its divisors (36).

It is not an unprimeable number, because it can be changed into a prime (28731997769) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 120849 + ... + 268455.

Almost surely, 2^28731997764 is an apocalyptic number.

It is an amenable number.

28731997764 is an abundant number, since it is smaller than the sum of its proper divisors (43910032060).

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

28731997764 is a wasteful number, since it uses less digits than its factorization.

28731997764 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 153024 (or 153019 counting only the distinct ones).

The product of its digits is 32006016, while the sum is 63.

The spelling of 28731997764 in words is "twenty-eight billion, seven hundred thirty-one million, nine hundred ninety-seven thousand, seven hundred sixty-four".