649993521 has 16 divisors (see below), whose sum is σ = 918216000. Its totient is φ = 407582208.

The previous prime is 649993517. The next prime is 649993529. The reversal of 649993521 is 125399946.

It is not a de Polignac number, because 649993521 - 2² = 649993517 is a prime.

It is not an unprimeable number, because it can be changed into a prime (649993529) 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, 108205 + ... + 114053.

It is an arithmetic number, because the mean of its divisors is an integer number (57388500).

Almost surely, 2^649993521 is an apocalyptic number.

It is an amenable number.

649993521 is a deficient number, since it is larger than the sum of its proper divisors (268222479).

649993521 is a wasteful number, since it uses less digits than its factorization.

649993521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8048.

The product of its digits is 524880, while the sum is 48.

The square root of 649993521 is about 25494.9705040033. The cubic root of 649993521 is about 866.2362271964.

The spelling of 649993521 in words is "six hundred forty-nine million, nine hundred ninety-three thousand, five hundred twenty-one".