20439812880 has 60 divisors (see below), whose sum is σ = 68643707340. Its totient is φ = 5450616576.

The previous prime is 20439812879. The next prime is 20439812903. The reversal of 20439812880 is 8821893402.

It can be written as a sum of positive squares in 2 ways, for example, as 11161499904 + 9278312976 = 105648^2 + 96324^2 .

It is a tau number, because it is divible by the number of its divisors (60).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14193595 + ... + 14195034.

It is an arithmetic number, because the mean of its divisors is an integer number (1144061789).

Almost surely, 2^20439812880 is an apocalyptic number.

20439812880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20439812880 is an abundant number, since it is smaller than the sum of its proper divisors (48203894460).

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

20439812880 is a wasteful number, since it uses less digits than its factorization.

20439812880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28388648 (or 28388639 counting only the distinct ones).

The product of its (nonzero) digits is 221184, while the sum is 45.

The spelling of 20439812880 in words is "twenty billion, four hundred thirty-nine million, eight hundred twelve thousand, eight hundred eighty".