620646640 has 20 divisors (see below), whose sum is σ = 1443003624. Its totient is φ = 248258624.

The previous prime is 620646623. The next prime is 620646671. The reversal of 620646640 is 46646026.

620646640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (20).

It is a junction number, because it is equal to n+sod(n) for n = 620646596 and 620646605.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3878962 + ... + 3879121.

Almost surely, 2^620646640 is an apocalyptic number.

It is an amenable number.

620646640 is an abundant number, since it is smaller than the sum of its proper divisors (822356984).

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

620646640 is a wasteful number, since it uses less digits than its factorization.

620646640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7758096 (or 7758090 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 34.

The square root of 620646640 is about 24912.7806557197. The cubic root of 620646640 is about 852.9982421841.

The spelling of 620646640 in words is "six hundred twenty million, six hundred forty-six thousand, six hundred forty".