20420561040 has 160 divisors (see below), whose sum is σ = 72061387776. Its totient is φ = 4735188480.

The previous prime is 20420561027. The next prime is 20420561047. The reversal of 20420561040 is 4016502402.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 20420561040.

It is not an unprimeable number, because it can be changed into a prime (20420561047) 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, 107434 + ... + 228873.

Almost surely, 2^20420561040 is an apocalyptic number.

20420561040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20420561040 is an abundant number, since it is smaller than the sum of its proper divisors (51640826736).

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

20420561040 is a wasteful number, since it uses less digits than its factorization.

20420561040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 336357 (or 336351 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 24.

The spelling of 20420561040 in words is "twenty billion, four hundred twenty million, five hundred sixty-one thousand, forty".