640077220 has 24 divisors (see below), whose sum is σ = 1344647808. Its totient is φ = 255938400.

The previous prime is 640077203. The next prime is 640077257. The reversal of 640077220 is 22770046.

640077220 is a modest number, since divided by 77220 gives 640 as remainder.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 88335 + ... + 95305.

It is an arithmetic number, because the mean of its divisors is an integer number (56026992).

Almost surely, 2^640077220 is an apocalyptic number.

It is an amenable number.

640077220 is an abundant number, since it is smaller than the sum of its proper divisors (704570588).

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

640077220 is a wasteful number, since it uses less digits than its factorization.

640077220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11571 (or 11569 counting only the distinct ones).

The product of its (nonzero) digits is 4704, while the sum is 28.

The square root of 640077220 is about 25299.7474295693. The cubic root of 640077220 is about 861.8085340870.

The spelling of 640077220 in words is "six hundred forty million, seventy-seven thousand, two hundred twenty".