21769980 has 48 divisors (see below), whose sum is σ = 61326720. Its totient is φ = 5770048.

The previous prime is 21769961. The next prime is 21770011. The reversal of 21769980 is 8996712.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9727 + ... + 11753.

It is an arithmetic number, because the mean of its divisors is an integer number (1277640).

Almost surely, 2^21769980 is an apocalyptic number.

21769980 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21769980 is an abundant number, since it is smaller than the sum of its proper divisors (39556740).

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

21769980 is a wasteful number, since it uses less digits than its factorization.

21769980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2218 (or 2216 counting only the distinct ones).

The product of its (nonzero) digits is 54432, while the sum is 42.

The square root of 21769980 is about 4665.8311156749. The cubic root of 21769980 is about 279.2239565599.

The spelling of 21769980 in words is "twenty-one million, seven hundred sixty-nine thousand, nine hundred eighty".