20936780 has 24 divisors (see below), whose sum is σ = 45386880. Its totient is φ = 8104320.

The previous prime is 20936779. The next prime is 20936789. The reversal of 20936780 is 8763902.

It is a self number, because there is not a number n which added to its sum of digits gives 20936780.

It is not an unprimeable number, because it can be changed into a prime (20936789) 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, 16265 + ... + 17504.

It is an arithmetic number, because the mean of its divisors is an integer number (1891120).

Almost surely, 2^20936780 is an apocalyptic number.

20936780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20936780 is an abundant number, since it is smaller than the sum of its proper divisors (24450100).

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

20936780 is a wasteful number, since it uses less digits than its factorization.

20936780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33809 (or 33807 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 35.

The square root of 20936780 is about 4575.6726281499. The cubic root of 20936780 is about 275.6152834984.

The spelling of 20936780 in words is "twenty million, nine hundred thirty-six thousand, seven hundred eighty".