20791880 has 16 divisors (see below), whose sum is σ = 46781820. Its totient is φ = 8316736.

The previous prime is 20791877. The next prime is 20791937. The reversal of 20791880 is 8819702.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 20448484 + 343396 = 4522^2 + 586^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 20791880.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 259859 + ... + 259938.

Almost surely, 2^20791880 is an apocalyptic number.

20791880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20791880 is an abundant number, since it is smaller than the sum of its proper divisors (25989940).

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

20791880 is a wasteful number, since it uses less digits than its factorization.

20791880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 519808 (or 519804 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 35.

The square root of 20791880 is about 4559.8113996085. The cubic root of 20791880 is about 274.9779817082.

The spelling of 20791880 in words is "twenty million, seven hundred ninety-one thousand, eight hundred eighty".