640121037 has 8 divisors (see below), whose sum is σ = 856240320. Its totient is φ = 425374560.

The previous prime is 640121023. The next prime is 640121047. The reversal of 640121037 is 730121046.

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

It is not a de Polignac number, because 640121037 - 2⁸ = 640120781 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 640120998 and 640121016.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640121047) 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, 342112 + ... + 343977.

It is an arithmetic number, because the mean of its divisors is an integer number (107030040).

Almost surely, 2^640121037 is an apocalyptic number.

It is an amenable number.

640121037 is a deficient number, since it is larger than the sum of its proper divisors (216119283).

640121037 is a wasteful number, since it uses less digits than its factorization.

640121037 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 686403.

The product of its (nonzero) digits is 1008, while the sum is 24.

The square root of 640121037 is about 25300.6133720114. The cubic root of 640121037 is about 861.8281989033.

Subtracting 640121037 from its reverse (730121046), we obtain a palindrome (90000009).

The spelling of 640121037 in words is "six hundred forty million, one hundred twenty-one thousand, thirty-seven".