640604100631 has 8 divisors (see below), whose sum is σ = 698983837200. Its totient is φ = 582248197440.

The previous prime is 640604100613. The next prime is 640604100649. The reversal of 640604100631 is 136001406046.

It is an interprime number because it is at equal distance from previous prime (640604100613) and next prime (640604100649).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 640604100631 - 2⁷ = 640604100503 is a prime.

It is a super-2 number, since 2×640604100631² (a number of 24 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 640604100593 and 640604100602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640604100931) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5902116 + ... + 6009673.

It is an arithmetic number, because the mean of its divisors is an integer number (87372979650).

Almost surely, 2^640604100631 is an apocalyptic number.

640604100631 is a deficient number, since it is larger than the sum of its proper divisors (58379736569).

640604100631 is a wasteful number, since it uses less digits than its factorization.

640604100631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11916689.

The product of its (nonzero) digits is 10368, while the sum is 31.

Adding to 640604100631 its reverse (136001406046), we get a palindrome (776605506677).

The spelling of 640604100631 in words is "six hundred forty billion, six hundred four million, one hundred thousand, six hundred thirty-one".