649691901278 has 32 divisors (see below), whose sum is σ = 1115574379200. Its totient is φ = 277985562624.

The previous prime is 649691901167. The next prime is 649691901311. The reversal of 649691901278 is 872109196946.

It is a self number, because there is not a number n which added to its sum of digits gives 649691901278.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21957278 + ... + 21986846.

It is an arithmetic number, because the mean of its divisors is an integer number (34861699350).

Almost surely, 2^649691901278 is an apocalyptic number.

649691901278 is a deficient number, since it is larger than the sum of its proper divisors (465882477922).

649691901278 is a wasteful number, since it uses less digits than its factorization.

649691901278 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32084.

The product of its (nonzero) digits is 11757312, while the sum is 62.

The spelling of 649691901278 in words is "six hundred forty-nine billion, six hundred ninety-one million, nine hundred one thousand, two hundred seventy-eight".