649697761 has 4 divisors (see below), whose sum is σ = 683892400. Its totient is φ = 615503124.

The previous prime is 649697753. The next prime is 649697771. The reversal of 649697761 is 167796946.

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.

It is a cyclic number.

It is not a de Polignac number, because 649697761 - 2³ = 649697753 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (649697731) 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, 17097291 + ... + 17097328.

It is an arithmetic number, because the mean of its divisors is an integer number (170973100).

Almost surely, 2^649697761 is an apocalyptic number.

It is an amenable number.

649697761 is a deficient number, since it is larger than the sum of its proper divisors (34194639).

649697761 is a wasteful number, since it uses less digits than its factorization.

649697761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34194638.

The product of its digits is 3429216, while the sum is 55.

The square root of 649697761 is about 25489.1694843124. The cubic root of 649697761 is about 866.1048223508.

The spelling of 649697761 in words is "six hundred forty-nine million, six hundred ninety-seven thousand, seven hundred sixty-one".