20764880 has 40 divisors (see below), whose sum is σ = 48726792. Its totient is φ = 8228864.

The previous prime is 20764879. The next prime is 20764889. The reversal of 20764880 is 8846702.

It can be written as a sum of positive squares in 4 ways, for example, as 7744 + 20757136 = 88^2 + 4556^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a self number, because there is not a number n which added to its sum of digits gives 20764880.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20764889) 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, 7892 + ... + 10188.

Almost surely, 2^20764880 is an apocalyptic number.

20764880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20764880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24363396).

20764880 is an abundant number, since it is smaller than the sum of its proper divisors (27961912).

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

20764880 is a wasteful number, since it uses less digits than its factorization.

20764880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2423 (or 2417 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 35.

The square root of 20764880 is about 4556.8497890538. The cubic root of 20764880 is about 274.8589028248.

The spelling of 20764880 in words is "twenty million, seven hundred sixty-four thousand, eight hundred eighty".