28921061568 has 56 divisors (see below), whose sum is σ = 87451785472. Its totient is φ = 8263160064.

The previous prime is 28921061567. The next prime is 28921061569. The reversal of 28921061568 is 86516012982.

It is an interprime number because it is at equal distance from previous prime (28921061567) and next prime (28921061569).

It is a tau number, because it is divible by the number of its divisors (56).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is not an unprimeable number, because it can be changed into a prime (28921061567) 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, 10757980 + ... + 10760667.

Almost surely, 2^28921061568 is an apocalyptic number.

28921061568 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

28921061568 is an abundant number, since it is smaller than the sum of its proper divisors (58530723904).

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

28921061568 is a wasteful number, since it uses less digits than its factorization.

28921061568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21518669 (or 21518659 counting only the distinct ones).

The product of its (nonzero) digits is 414720, while the sum is 48.

The spelling of 28921061568 in words is "twenty-eight billion, nine hundred twenty-one million, sixty-one thousand, five hundred sixty-eight".