28156029521 has 2 divisors, whose sum is σ = 28156029522. Its totient is φ = 28156029520.

The previous prime is 28156029511. The next prime is 28156029593. The reversal of 28156029521 is 12592065182.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25838955025 + 2317074496 = 160745^2 + 48136^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28156029521 is a prime.

It is not a weakly prime, because it can be changed into another prime (28156029511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14078014760 + 14078014761.

It is an arithmetic number, because the mean of its divisors is an integer number (14078014761).

Almost surely, 2^28156029521 is an apocalyptic number.

It is an amenable number.

28156029521 is a deficient number, since it is larger than the sum of its proper divisors (1).

28156029521 is an equidigital number, since it uses as much as digits as its factorization.

28156029521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 86400, while the sum is 41.

The spelling of 28156029521 in words is "twenty-eight billion, one hundred fifty-six million, twenty-nine thousand, five hundred twenty-one".