28311977 has 4 divisors (see below), whose sum is σ = 28322640. Its totient is φ = 28301316.

The previous prime is 28311973. The next prime is 28312003. The reversal of 28311977 is 77911382.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 28311977 - 2² = 28311973 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28311977.

It is not an unprimeable number, because it can be changed into a prime (28311971) 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, 2174 + ... + 7832.

It is an arithmetic number, because the mean of its divisors is an integer number (7080660).

Almost surely, 2^28311977 is an apocalyptic number.

It is an amenable number.

28311977 is a deficient number, since it is larger than the sum of its proper divisors (10663).

28311977 is an equidigital number, since it uses as much as digits as its factorization.

28311977 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10662.

The product of its digits is 21168, while the sum is 38.

The square root of 28311977 is about 5320.9000178541. The cubic root of 28311977 is about 304.7825270477.

The spelling of 28311977 in words is "twenty-eight million, three hundred eleven thousand, nine hundred seventy-seven".