640260131 has 16 divisors (see below), whose sum is σ = 768144384. Its totient is φ = 521768544.

The previous prime is 640260113. The next prime is 640260133. The reversal of 640260131 is 131062046.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 640260131 - 2¹⁰ = 640259107 is a prime.

It is a super-2 number, since 2×640260131² = 819866070696274322, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a junction number, because it is equal to n+sod(n) for n = 640260097 and 640260106.

It is not an unprimeable number, because it can be changed into a prime (640260133) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14981 + ... + 38793.

It is an arithmetic number, because the mean of its divisors is an integer number (48009024).

Almost surely, 2^640260131 is an apocalyptic number.

640260131 is a deficient number, since it is larger than the sum of its proper divisors (127884253).

640260131 is a wasteful number, since it uses less digits than its factorization.

640260131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24010.

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 640260131 is about 25303.3620493404. The cubic root of 640260131 is about 861.8906175413.

The spelling of 640260131 in words is "six hundred forty million, two hundred sixty thousand, one hundred thirty-one".