20907531720 has 96 divisors (see below), whose sum is σ = 68048622720. Its totient is φ = 5567207040.

The previous prime is 20907531713. The next prime is 20907531727. The reversal of 20907531720 is 2713570902.

It is an interprime number because it is at equal distance from previous prime (20907531713) and next prime (20907531727).

It is a super-3 number, since 3×20907531720³ (a number of 32 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (20907531727) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 206737 + ... + 290783.

It is an arithmetic number, because the mean of its divisors is an integer number (708839820).

Almost surely, 2^20907531720 is an apocalyptic number.

20907531720 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 20907531720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34024311360).

20907531720 is an abundant number, since it is smaller than the sum of its proper divisors (47141091000).

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

20907531720 is a wasteful number, since it uses less digits than its factorization.

20907531720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84755 (or 84748 counting only the distinct ones).

The product of its (nonzero) digits is 26460, while the sum is 36.

The spelling of 20907531720 in words is "twenty billion, nine hundred seven million, five hundred thirty-one thousand, seven hundred twenty".