28181925 has 36 divisors (see below), whose sum is σ = 52357760. Its totient is φ = 15027120.

The previous prime is 28181911. The next prime is 28181941. The reversal of 28181925 is 52918182.

28181925 = T₁₄₈₉ + T₁₄₉₀ + ... + T₁₅₁₃.

It is not a de Polignac number, because 28181925 - 2⁸ = 28181669 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28181925.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 3756 + ... + 8394.

Almost surely, 2^28181925 is an apocalyptic number.

28181925 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

28181925 is a deficient number, since it is larger than the sum of its proper divisors (24175835).

28181925 is an equidigital number, since it uses as much as digits as its factorization.

28181925 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4664 (or 4647 counting only the distinct ones).

The product of its digits is 11520, while the sum is 36.

The square root of 28181925 is about 5308.6650864412. The cubic root of 28181925 is about 304.3151344581.

The spelling of 28181925 in words is "twenty-eight million, one hundred eighty-one thousand, nine hundred twenty-five".