640494270 has 128 divisors (see below), whose sum is σ = 1849236480. Its totient is φ = 156816000.

The previous prime is 640494269. The next prime is 640494287. The reversal of 640494270 is 72494046.

640494270 is a `hidden beast` number, since 640 + 4 + 9 + 4 + 2 + 7 + 0 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 880647 + ... + 881373.

It is an arithmetic number, because the mean of its divisors is an integer number (14447160).

Almost surely, 2^640494270 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 640494270, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (924618240).

640494270 is an abundant number, since it is smaller than the sum of its proper divisors (1208742210).

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

640494270 is a wasteful number, since it uses less digits than its factorization.

640494270 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1007 (or 1001 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 36.

The square root of 640494270 is about 25307.9882645776. The cubic root of 640494270 is about 861.9956673501.

The spelling of 640494270 in words is "six hundred forty million, four hundred ninety-four thousand, two hundred seventy".