649025409 has 4 divisors (see below), whose sum is σ = 865367216. Its totient is φ = 432683604.

The previous prime is 649025383. The next prime is 649025441. The reversal of 649025409 is 904520946.

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 not a de Polignac number, because 649025409 - 2⁷ = 649025281 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (649065409) 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, 108170899 + ... + 108170904.

It is an arithmetic number, because the mean of its divisors is an integer number (216341804).

Almost surely, 2^649025409 is an apocalyptic number.

It is an amenable number.

649025409 is a deficient number, since it is larger than the sum of its proper divisors (216341807).

649025409 is a wasteful number, since it uses less digits than its factorization.

649025409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 216341806.

The product of its (nonzero) digits is 77760, while the sum is 39.

The square root of 649025409 is about 25475.9770960801. The cubic root of 649025409 is about 865.8059509178.

The spelling of 649025409 in words is "six hundred forty-nine million, twenty-five thousand, four hundred nine".