20909531280 has 160 divisors (see below), whose sum is σ = 73150853760. Its totient is φ = 4894167040.

The previous prime is 20909531273. The next prime is 20909531281. The reversal of 20909531280 is 8213590902.

It is not an unprimeable number, because it can be changed into a prime (20909531281) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 59997 + ... + 213116.

It is an arithmetic number, because the mean of its divisors is an integer number (457192836).

Almost surely, 2^20909531280 is an apocalyptic number.

20909531280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20909531280 is an abundant number, since it is smaller than the sum of its proper divisors (52241322480).

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

20909531280 is a wasteful number, since it uses less digits than its factorization.

20909531280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 273169 (or 273163 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 39.

The spelling of 20909531280 in words is "twenty billion, nine hundred nine million, five hundred thirty-one thousand, two hundred eighty".