649453661 has 4 divisors (see below), whose sum is σ = 663271872. Its totient is φ = 635635452.

The previous prime is 649453657. The next prime is 649453697. The reversal of 649453661 is 166354946.

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 649453661 - 2² = 649453657 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 (649450661) 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, 6909035 + ... + 6909128.

It is an arithmetic number, because the mean of its divisors is an integer number (165817968).

Almost surely, 2^649453661 is an apocalyptic number.

It is an amenable number.

649453661 is a deficient number, since it is larger than the sum of its proper divisors (13818211).

649453661 is a wasteful number, since it uses less digits than its factorization.

649453661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13818210.

The product of its digits is 466560, while the sum is 44.

The square root of 649453661 is about 25484.3807262409. The cubic root of 649453661 is about 865.9963397698.

The spelling of 649453661 in words is "six hundred forty-nine million, four hundred fifty-three thousand, six hundred sixty-one".