21977277 has 16 divisors (see below), whose sum is σ = 35459712. Its totient is φ = 11819520.

The previous prime is 21977261. The next prime is 21977279. The reversal of 21977277 is 77277912.

It is not a de Polignac number, because 21977277 - 2⁴ = 21977261 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21977279) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30424 + ... + 31137.

It is an arithmetic number, because the mean of its divisors is an integer number (2216232).

Almost surely, 2^21977277 is an apocalyptic number.

It is an amenable number.

21977277 is a deficient number, since it is larger than the sum of its proper divisors (13482435).

21977277 is a wasteful number, since it uses less digits than its factorization.

21977277 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61588.

The product of its digits is 86436, while the sum is 42.

The square root of 21977277 is about 4687.9928540901. The cubic root of 21977277 is about 280.1074290150.

The spelling of 21977277 in words is "twenty-one million, nine hundred seventy-seven thousand, two hundred seventy-seven".