649120840 has 16 divisors (see below), whose sum is σ = 1460521980. Its totient is φ = 259648320.

The previous prime is 649120793. The next prime is 649120841. The reversal of 649120840 is 48021946.

It can be written as a sum of positive squares in 2 ways, for example, as 584575684 + 64545156 = 24178^2 + 8034^2 .

It is a junction number, because it is equal to n+sod(n) for n = 649120796 and 649120805.

It is not an unprimeable number, because it can be changed into a prime (649120841) 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, 8113971 + ... + 8114050.

Almost surely, 2^649120840 is an apocalyptic number.

It is an amenable number.

649120840 is an abundant number, since it is smaller than the sum of its proper divisors (811401140).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

649120840 is a wasteful number, since it uses less digits than its factorization.

649120840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16228032 (or 16228028 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 34.

The square root of 649120840 is about 25477.8499877835. The cubic root of 649120840 is about 865.8483841196.

The spelling of 649120840 in words is "six hundred forty-nine million, one hundred twenty thousand, eight hundred forty".