20917320 has 32 divisors (see below), whose sum is σ = 62752320. Its totient is φ = 5577920.

The previous prime is 20917313. The next prime is 20917331. The reversal of 20917320 is 2371902.

It is a super-3 number, since 3×20917320³ (a number of 23 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

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, 87036 + ... + 87275.

It is an arithmetic number, because the mean of its divisors is an integer number (1961010).

Almost surely, 2^20917320 is an apocalyptic number.

20917320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20917320 is an abundant number, since it is smaller than the sum of its proper divisors (41835000).

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

20917320 is a wasteful number, since it uses less digits than its factorization.

20917320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174325 (or 174321 counting only the distinct ones).

The product of its (nonzero) digits is 756, while the sum is 24.

The square root of 20917320 is about 4573.5456704837. The cubic root of 20917320 is about 275.5298654606.

The spelling of 20917320 in words is "twenty million, nine hundred seventeen thousand, three hundred twenty".