28181308 has 12 divisors (see below), whose sum is σ = 52218432. Its totient is φ = 13261760.

The previous prime is 28181299. The next prime is 28181317. The reversal of 28181308 is 80318182.

It is an interprime number because it is at equal distance from previous prime (28181299) and next prime (28181317).

It is a super-2 number, since 2×28181308² = 1588372241181728, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 28181308.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 207148 + ... + 207283.

It is an arithmetic number, because the mean of its divisors is an integer number (4351536).

Almost surely, 2^28181308 is an apocalyptic number.

It is an amenable number.

28181308 is a deficient number, since it is larger than the sum of its proper divisors (24037124).

28181308 is a wasteful number, since it uses less digits than its factorization.

28181308 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 414452 (or 414450 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 31.

The square root of 28181308 is about 5308.6069735854. The cubic root of 28181308 is about 304.3129136042.

The spelling of 28181308 in words is "twenty-eight million, one hundred eighty-one thousand, three hundred eight".