640258634 has 16 divisors (see below), whose sum is σ = 965690880. Its totient is φ = 318366720.

The previous prime is 640258627. The next prime is 640258639. The reversal of 640258634 is 436852046.

It is a super-2 number, since 2×640258634² = 819862236823091912, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (640258639) 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, 434519 + ... + 435989.

It is an arithmetic number, because the mean of its divisors is an integer number (60355680).

Almost surely, 2^640258634 is an apocalyptic number.

640258634 is a deficient number, since it is larger than the sum of its proper divisors (325432246).

640258634 is a wasteful number, since it uses less digits than its factorization.

640258634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2525.

The product of its (nonzero) digits is 138240, while the sum is 38.

The square root of 640258634 is about 25303.3324682738. The cubic root of 640258634 is about 861.8899458085.

The spelling of 640258634 in words is "six hundred forty million, two hundred fifty-eight thousand, six hundred thirty-four".