21977000 has 32 divisors (see below), whose sum is σ = 51428520. Its totient is φ = 8790400.

The previous prime is 21976979. The next prime is 21977023. The reversal of 21977000 is 77912.

It can be written as a sum of positive squares in 4 ways, for example, as 6120676 + 15856324 = 2474^2 + 3982^2 .

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, 9989 + ... + 11988.

Almost surely, 2^21977000 is an apocalyptic number.

21977000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21977000 is an abundant number, since it is smaller than the sum of its proper divisors (29451520).

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

21977000 is a wasteful number, since it uses less digits than its factorization.

21977000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21998 (or 21984 counting only the distinct ones).

The product of its (nonzero) digits is 882, while the sum is 26.

The square root of 21977000 is about 4687.9633104366. The cubic root of 21977000 is about 280.1062521922.

The spelling of 21977000 in words is "twenty-one million, nine hundred seventy-seven thousand".