649918672 has 20 divisors (see below), whose sum is σ = 1356080740. Its totient is φ = 299962368.

The previous prime is 649918669. The next prime is 649918699. The reversal of 649918672 is 276819946.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 109077136 + 540841536 = 10444^2 + 23256^2 .

It is a Harshad number since it is a multiple of its sum of digits (52).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1562097 + ... + 1562512.

It is an arithmetic number, because the mean of its divisors is an integer number (67804037).

Almost surely, 2^649918672 is an apocalyptic number.

It is an amenable number.

649918672 is an abundant number, since it is smaller than the sum of its proper divisors (706162068).

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

649918672 is a wasteful number, since it uses less digits than its factorization.

649918672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3124630 (or 3124624 counting only the distinct ones).

The product of its digits is 1306368, while the sum is 52.

The square root of 649918672 is about 25493.5025447662. The cubic root of 649918672 is about 866.2029758884.

The spelling of 649918672 in words is "six hundred forty-nine million, nine hundred eighteen thousand, six hundred seventy-two".