20992580 has 72 divisors (see below), whose sum is σ = 53012736. Its totient is φ = 6955200.

The previous prime is 20992567. The next prime is 20992589. The reversal of 20992580 is 8529902.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a self number, because there is not a number n which added to its sum of digits gives 20992580.

It is not an unprimeable number, because it can be changed into a prime (20992589) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 30035 + ... + 30725.

It is an arithmetic number, because the mean of its divisors is an integer number (736288).

Almost surely, 2^20992580 is an apocalyptic number.

20992580 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 20992580, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26506368).

20992580 is an abundant number, since it is smaller than the sum of its proper divisors (32020156).

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

20992580 is a wasteful number, since it uses less digits than its factorization.

20992580 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 745 (or 736 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 35.

The square root of 20992580 is about 4581.7660350568. The cubic root of 20992580 is about 275.8599198144.

The spelling of 20992580 in words is "twenty million, nine hundred ninety-two thousand, five hundred eighty".