20719875136 has 63 divisors (see below), whose sum is σ = 43439767959. Its totient is φ = 9804313728.

The previous prime is 20719875131. The next prime is 20719875157. The reversal of 20719875136 is 63157891702.

It is a happy number.

The square root of 20719875136 is 143944.

It is a perfect power (a square), and thus also a powerful number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20719875136.

It is not an unprimeable number, because it can be changed into a prime (20719875131) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 21879015 + ... + 21879961.

Almost surely, 2^20719875136 is an apocalyptic number.

20719875136 is the 143944-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20719875136

20719875136 is an abundant number, since it is smaller than the sum of its proper divisors (22719892823).

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

20719875136 is an frugal number, since it uses more digits than its factorization.

20719875136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1944 (or 968 counting only the distinct ones).

The product of its (nonzero) digits is 635040, while the sum is 49.

Multiplying 20719875136 by its sum of digits (49), we get a square (1015273881664 = 1007608²).

The spelling of 20719875136 in words is "twenty billion, seven hundred nineteen million, eight hundred seventy-five thousand, one hundred thirty-six".