21977120 has 48 divisors (see below), whose sum is σ = 56645568. Its totient is φ = 7991040.

The previous prime is 21977113. The next prime is 21977143. The reversal of 21977120 is 2177912.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4484 + ... + 8003.

It is an arithmetic number, because the mean of its divisors is an integer number (1180116).

Almost surely, 2^21977120 is an apocalyptic number.

21977120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21977120 is an abundant number, since it is smaller than the sum of its proper divisors (34668448).

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

21977120 is a wasteful number, since it uses less digits than its factorization.

21977120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12513 (or 12505 counting only the distinct ones).

The product of its (nonzero) digits is 1764, while the sum is 29.

The square root of 21977120 is about 4687.9761091541. The cubic root of 21977120 is about 280.1067620083.

The spelling of 21977120 in words is "twenty-one million, nine hundred seventy-seven thousand, one hundred twenty".