640253434 has 16 divisors (see below), whose sum is σ = 976043520. Its totient is φ = 314925520.

The previous prime is 640253429. The next prime is 640253441. The reversal of 640253434 is 434352046.

It is a junction number, because it is equal to n+sod(n) for n = 640253396 and 640253405.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 63312 + ... + 72724.

It is an arithmetic number, because the mean of its divisors is an integer number (61002720).

Almost surely, 2^640253434 is an apocalyptic number.

640253434 is a deficient number, since it is larger than the sum of its proper divisors (335790086).

640253434 is a wasteful number, since it uses less digits than its factorization.

640253434 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9965.

The product of its (nonzero) digits is 34560, while the sum is 31.

The square root of 640253434 is about 25303.2297148012. The cubic root of 640253434 is about 861.8876124598.

The spelling of 640253434 in words is "six hundred forty million, two hundred fifty-three thousand, four hundred thirty-four".