640451426220 has 36 divisors (see below), whose sum is σ = 1942702660080. Its totient is φ = 170787046944.

The previous prime is 640451426201. The next prime is 640451426261. The reversal of 640451426220 is 22624154046.

640451426220 is a `hidden beast` number, since 6 + 4 + 0 + 4 + 5 + 1 + 426 + 220 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

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

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, 1779031560 + ... + 1779031919.

It is an arithmetic number, because the mean of its divisors is an integer number (53963962780).

Almost surely, 2^640451426220 is an apocalyptic number.

640451426220 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

640451426220 is an abundant number, since it is smaller than the sum of its proper divisors (1302251233860).

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

640451426220 is a wasteful number, since it uses less digits than its factorization.

640451426220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3558063494 (or 3558063489 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 36.

The spelling of 640451426220 in words is "six hundred forty billion, four hundred fifty-one million, four hundred twenty-six thousand, two hundred twenty".