649820918 has 4 divisors (see below), whose sum is σ = 974731380. Its totient is φ = 324910458.

The previous prime is 649820917. The next prime is 649820933. The reversal of 649820918 is 819028946.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (649820911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 162455228 + ... + 162455231.

It is an arithmetic number, because the mean of its divisors is an integer number (243682845).

Almost surely, 2^649820918 is an apocalyptic number.

649820918 is a deficient number, since it is larger than the sum of its proper divisors (324910462).

649820918 is a wasteful number, since it uses less digits than its factorization.

649820918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 324910461.

The product of its (nonzero) digits is 248832, while the sum is 47.

The square root of 649820918 is about 25491.5852390549. The cubic root of 649820918 is about 866.1595452998.

The spelling of 649820918 in words is "six hundred forty-nine million, eight hundred twenty thousand, nine hundred eighteen".