20721187470 has 32 divisors (see below), whose sum is σ = 49873370400. Its totient is φ = 5509814400.

The previous prime is 20721187469. The next prime is 20721187499. The reversal of 20721187470 is 7478112702.

It is a super-2 number, since 2×20721187470² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

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, 979081 + ... + 1000020.

It is an arithmetic number, because the mean of its divisors is an integer number (1558542825).

Almost surely, 2^20721187470 is an apocalyptic number.

20721187470 is an abundant number, since it is smaller than the sum of its proper divisors (29152182930).

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

20721187470 is a wasteful number, since it uses less digits than its factorization.

20721187470 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1979460.

The product of its (nonzero) digits is 43904, while the sum is 39.

The spelling of 20721187470 in words is "twenty billion, seven hundred twenty-one million, one hundred eighty-seven thousand, four hundred seventy".