28402837681 has 2 divisors, whose sum is σ = 28402837682. Its totient is φ = 28402837680.

The previous prime is 28402837663. The next prime is 28402837721. The reversal of 28402837681 is 18673820482.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26851738225 + 1551099456 = 163865^2 + 39384^2 .

It is a cyclic number.

It is not a de Polignac number, because 28402837681 - 2¹⁷ = 28402706609 is a prime.

It is a super-2 number, since 2×28402837681² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (28402837381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14201418840 + 14201418841.

It is an arithmetic number, because the mean of its divisors is an integer number (14201418841).

Almost surely, 2^28402837681 is an apocalyptic number.

It is an amenable number.

28402837681 is a deficient number, since it is larger than the sum of its proper divisors (1).

28402837681 is an equidigital number, since it uses as much as digits as its factorization.

28402837681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1032192, while the sum is 49.

The spelling of 28402837681 in words is "twenty-eight billion, four hundred two million, eight hundred thirty-seven thousand, six hundred eighty-one".