28725881 has 2 divisors, whose sum is σ = 28725882. Its totient is φ = 28725880.

The previous prime is 28725877. The next prime is 28725899. The reversal of 28725881 is 18852782.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21939856 + 6786025 = 4684^2 + 2605^2 .

It is a cyclic number.

It is not a de Polignac number, because 28725881 - 2² = 28725877 is a prime.

It is a super-2 number, since 2×28725881² = 1650352478452322, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28725821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14362940 + 14362941.

It is an arithmetic number, because the mean of its divisors is an integer number (14362941).

Almost surely, 2^28725881 is an apocalyptic number.

It is an amenable number.

28725881 is a deficient number, since it is larger than the sum of its proper divisors (1).

28725881 is an equidigital number, since it uses as much as digits as its factorization.

28725881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 71680, while the sum is 41.

The square root of 28725881 is about 5359.6530671304. The cubic root of 28725881 is about 306.2605929419.

The spelling of 28725881 in words is "twenty-eight million, seven hundred twenty-five thousand, eight hundred eighty-one".