21773920 has 48 divisors (see below), whose sum is σ = 58792608. Its totient is φ = 7464960.

The previous prime is 21773863. The next prime is 21773951. The reversal of 21773920 is 2937712.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8601 + ... + 10840.

It is an arithmetic number, because the mean of its divisors is an integer number (1224846).

Almost surely, 2^21773920 is an apocalyptic number.

21773920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21773920 is an abundant number, since it is smaller than the sum of its proper divisors (37018688).

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

21773920 is a wasteful number, since it uses less digits than its factorization.

21773920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19463 (or 19455 counting only the distinct ones).

The product of its (nonzero) digits is 5292, while the sum is 31.

The square root of 21773920 is about 4666.2533150269. The cubic root of 21773920 is about 279.2408004894.

The spelling of 21773920 in words is "twenty-one million, seven hundred seventy-three thousand, nine hundred twenty".