20818513000 has 64 divisors (see below), whose sum is σ = 48741610320. Its totient is φ = 8322912000.

The previous prime is 20818512983. The next prime is 20818513031. The reversal of 20818513000 is 31581802.

It can be written as a sum of positive squares in 8 ways, for example, as 58890276 + 20759622724 = 7674^2 + 144082^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 20818513000.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2336554 + ... + 2345446.

Almost surely, 2^20818513000 is an apocalyptic number.

20818513000 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 20818513000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24370805160).

20818513000 is an abundant number, since it is smaller than the sum of its proper divisors (27923097320).

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

20818513000 is a wasteful number, since it uses less digits than its factorization.

20818513000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11255 (or 11241 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 28.

The spelling of 20818513000 in words is "twenty billion, eight hundred eighteen million, five hundred thirteen thousand".