640647030 has 32 divisors (see below), whose sum is σ = 1543554144. Its totient is φ = 170172416.

The previous prime is 640647013. The next prime is 640647031. The reversal of 640647030 is 30746046.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640647031) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33837 + ... + 49256.

It is an arithmetic number, because the mean of its divisors is an integer number (48236067).

Almost surely, 2^640647030 is an apocalyptic number.

640647030 is an abundant number, since it is smaller than the sum of its proper divisors (902907114).

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

640647030 is a wasteful number, since it uses less digits than its factorization.

640647030 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83360.

The product of its (nonzero) digits is 12096, while the sum is 30.

The square root of 640647030 is about 25311.0061040647. The cubic root of 640647030 is about 862.0641915077.

The spelling of 640647030 in words is "six hundred forty million, six hundred forty-seven thousand, thirty".