28691156 has 12 divisors (see below), whose sum is σ = 54071892. Its totient is φ = 13242048.

The previous prime is 28691153. The next prime is 28691161. The reversal of 28691156 is 65119682.

It can be written as a sum of positive squares in 2 ways, for example, as 8584900 + 20106256 = 2930^2 + 4484^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28691153) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 275825 + ... + 275928.

It is an arithmetic number, because the mean of its divisors is an integer number (4505991).

Almost surely, 2^28691156 is an apocalyptic number.

28691156 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

28691156 is a deficient number, since it is larger than the sum of its proper divisors (25380736).

28691156 is a wasteful number, since it uses less digits than its factorization.

28691156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 551770 (or 551768 counting only the distinct ones).

The product of its digits is 25920, while the sum is 38.

The square root of 28691156 is about 5356.4126054665. The cubic root of 28691156 is about 306.1371364758.

The spelling of 28691156 in words is "twenty-eight million, six hundred ninety-one thousand, one hundred fifty-six".