20865380 has 24 divisors (see below), whose sum is σ = 43908480. Its totient is φ = 8328800.

The previous prime is 20865367. The next prime is 20865389. The reversal of 20865380 is 8356802.

It is not an unprimeable number, because it can be changed into a prime (20865389) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13655 + ... + 15105.

It is an arithmetic number, because the mean of its divisors is an integer number (1829520).

Almost surely, 2^20865380 is an apocalyptic number.

20865380 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20865380 is an abundant number, since it is smaller than the sum of its proper divisors (23043100).

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

20865380 is a wasteful number, since it uses less digits than its factorization.

20865380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2179 (or 2177 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 32.

The square root of 20865380 is about 4567.8638333470. The cubic root of 20865380 is about 275.3016194766.

The spelling of 20865380 in words is "twenty million, eight hundred sixty-five thousand, three hundred eighty".