640400630760 has 128 divisors (see below), whose sum is σ = 2328729609600. Its totient is φ = 155248634880.

The previous prime is 640400630699. The next prime is 640400630767. The reversal of 640400630760 is 67036004046.

640400630760 is a `hidden beast` number, since 640 + 4 + 0 + 0 + 6 + 3 + 0 + 7 + 6 + 0 = 666.

It is a super-2 number, since 2×640400630760² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (640400630767) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 26941009 + ... + 26964768.

It is an arithmetic number, because the mean of its divisors is an integer number (18193200075).

Almost surely, 2^640400630760 is an apocalyptic number.

640400630760 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

640400630760 is an abundant number, since it is smaller than the sum of its proper divisors (1688328978840).

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

640400630760 is a wasteful number, since it uses less digits than its factorization.

640400630760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53905808 (or 53905798 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 36.

The spelling of 640400630760 in words is "six hundred forty billion, four hundred million, six hundred thirty thousand, seven hundred sixty".