20707780 has 24 divisors (see below), whose sum is σ = 43690752. Its totient is φ = 8244192.

The previous prime is 20707759. The next prime is 20707781. The reversal of 20707780 is 8770702.

It is a hoax number, since the sum of its digits (31) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (20707781) 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, 2139 + ... + 6781.

It is an arithmetic number, because the mean of its divisors is an integer number (1820448).

Almost surely, 2^20707780 is an apocalyptic number.

20707780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20707780 is an abundant number, since it is smaller than the sum of its proper divisors (22982972).

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

20707780 is a wasteful number, since it uses less digits than its factorization.

20707780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4875 (or 4873 counting only the distinct ones).

The product of its (nonzero) digits is 5488, while the sum is 31.

The square root of 20707780 is about 4550.5801827899. The cubic root of 20707780 is about 274.6067326368.

The spelling of 20707780 in words is "twenty million, seven hundred seven thousand, seven hundred eighty".