28131377 has 4 divisors (see below), whose sum is σ = 28608240. Its totient is φ = 27654516.

The previous prime is 28131373. The next prime is 28131401. The reversal of 28131377 is 77313182.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 28131377 - 2² = 28131373 is a prime.

It is a super-2 number, since 2×28131377² = 1582748743832258, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28131373) 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, 238343 + ... + 238460.

It is an arithmetic number, because the mean of its divisors is an integer number (7152060).

Almost surely, 2^28131377 is an apocalyptic number.

It is an amenable number.

28131377 is a deficient number, since it is larger than the sum of its proper divisors (476863).

28131377 is an equidigital number, since it uses as much as digits as its factorization.

28131377 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 476862.

The product of its digits is 7056, while the sum is 32.

The square root of 28131377 is about 5303.9020541484. The cubic root of 28131377 is about 304.1330824578.

The spelling of 28131377 in words is "twenty-eight million, one hundred thirty-one thousand, three hundred seventy-seven".