28721335524 has 24 divisors (see below), whose sum is σ = 76590228288. Its totient is φ = 8206095840.

The previous prime is 28721335501. The next prime is 28721335529. The reversal of 28721335524 is 42553312782.

It is a super-2 number, since 2×28721335524² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is not an unprimeable number, because it can be changed into a prime (28721335529) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 170960247 + ... + 170960414.

It is an arithmetic number, because the mean of its divisors is an integer number (3191259512).

Almost surely, 2^28721335524 is an apocalyptic number.

It is an amenable number.

28721335524 is an abundant number, since it is smaller than the sum of its proper divisors (47868892764).

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

28721335524 is a wasteful number, since it uses less digits than its factorization.

28721335524 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 341920675 (or 341920673 counting only the distinct ones).

The product of its digits is 403200, while the sum is 42.

The spelling of 28721335524 in words is "twenty-eight billion, seven hundred twenty-one million, three hundred thirty-five thousand, five hundred twenty-four".