640714261 has 4 divisors (see below), whose sum is σ = 698961024. Its totient is φ = 582467500.

The previous prime is 640714223. The next prime is 640714273. The reversal of 640714261 is 162417046.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 640714261 - 2¹¹ = 640712213 is a prime.

It is a super-2 number, since 2×640714261² = 821029528497552242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640714201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29123365 + ... + 29123386.

It is an arithmetic number, because the mean of its divisors is an integer number (174740256).

Almost surely, 2^640714261 is an apocalyptic number.

It is an amenable number.

640714261 is a deficient number, since it is larger than the sum of its proper divisors (58246763).

640714261 is a wasteful number, since it uses less digits than its factorization.

640714261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58246762.

The product of its (nonzero) digits is 8064, while the sum is 31.

The square root of 640714261 is about 25312.3341673580. The cubic root of 640714261 is about 862.0943461314.

The spelling of 640714261 in words is "six hundred forty million, seven hundred fourteen thousand, two hundred sixty-one".