640170390 has 32 divisors (see below), whose sum is σ = 1537387776. Its totient is φ = 170603360.

The previous prime is 640170383. The next prime is 640170397. The reversal of 640170390 is 93071046.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (640170383) and next prime (640170397).

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 (640170397) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 48439 + ... + 60221.

It is an arithmetic number, because the mean of its divisors is an integer number (48043368).

Almost surely, 2^640170390 is an apocalyptic number.

640170390 is an abundant number, since it is smaller than the sum of its proper divisors (897217386).

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

640170390 is a wasteful number, since it uses less digits than its factorization.

640170390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13604.

The product of its (nonzero) digits is 4536, while the sum is 30.

The square root of 640170390 is about 25301.5886852980. The cubic root of 640170390 is about 861.8503471698.

The spelling of 640170390 in words is "six hundred forty million, one hundred seventy thousand, three hundred ninety".