20356291720 has 32 divisors (see below), whose sum is σ = 46918773720. Its totient is φ = 7943918080.

The previous prime is 20356291699. The next prime is 20356291723. The reversal of 20356291720 is 2719265302.

It can be written as a sum of positive squares in 4 ways, for example, as 12335656356 + 8020635364 = 111066^2 + 89558^2 .

It is a super-2 number, since 2×20356291720² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20356291720.

It is not an unprimeable number, because it can be changed into a prime (20356291723) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6204547 + ... + 6207826.

Almost surely, 2^20356291720 is an apocalyptic number.

20356291720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20356291720 is an abundant number, since it is smaller than the sum of its proper divisors (26562482000).

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

20356291720 is a wasteful number, since it uses less digits than its factorization.

20356291720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12412425 (or 12412421 counting only the distinct ones).

The product of its (nonzero) digits is 45360, while the sum is 37.

The spelling of 20356291720 in words is "twenty billion, three hundred fifty-six million, two hundred ninety-one thousand, seven hundred twenty".