649816997 has 4 divisors (see below), whose sum is σ = 649871040. Its totient is φ = 649762956.

The previous prime is 649816991. The next prime is 649817011. The reversal of 649816997 is 799618946.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 649816997 - 2²² = 645622693 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (649816991) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68 + ... + 36050.

It is an arithmetic number, because the mean of its divisors is an integer number (162467760).

Almost surely, 2^649816997 is an apocalyptic number.

It is an amenable number.

649816997 is a deficient number, since it is larger than the sum of its proper divisors (54043).

649816997 is a wasteful number, since it uses less digits than its factorization.

649816997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54042.

The product of its digits is 5878656, while the sum is 59.

The square root of 649816997 is about 25491.5083312071. The cubic root of 649816997 is about 866.1578031694.

The spelling of 649816997 in words is "six hundred forty-nine million, eight hundred sixteen thousand, nine hundred ninety-seven".