21977912 has 16 divisors (see below), whose sum is σ = 44955000. Its totient is φ = 9989920.

The previous prime is 21977897. The next prime is 21977929.

21977912 is nontrivially palindromic in base 10.

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, 124787 + ... + 124962.

Almost surely, 2^21977912 is an apocalyptic number.

21977912 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21977912 is an abundant number, since it is smaller than the sum of its proper divisors (22977088).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21977912 is a wasteful number, since it uses less digits than its factorization.

21977912 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 249766 (or 249762 counting only the distinct ones).

The product of its digits is 15876, while the sum is 38.

The square root of 21977912 is about 4688.0605798134. The cubic root of 21977912 is about 280.1101267484.

The spelling of 21977912 in words is "twenty-one million, nine hundred seventy-seven thousand, nine hundred twelve".