640460370 has 128 divisors (see below), whose sum is σ = 1727308800. Its totient is φ = 150670080.

The previous prime is 640460357. The next prime is 640460371. The reversal of 640460370 is 73064046.

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

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (640460371) 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 63 ways as a sum of consecutive naturals, for example, 1834956 + ... + 1835304.

It is an arithmetic number, because the mean of its divisors is an integer number (13494600).

Almost surely, 2^640460370 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 640460370, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (863654400).

640460370 is an abundant number, since it is smaller than the sum of its proper divisors (1086848430).

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

640460370 is a wasteful number, since it uses less digits than its factorization.

640460370 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 520.

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

The square root of 640460370 is about 25307.3185067087. The cubic root of 640460370 is about 861.9804592158.

The spelling of 640460370 in words is "six hundred forty million, four hundred sixty thousand, three hundred seventy".