649905388 has 24 divisors (see below), whose sum is σ = 1294675200. Its totient is φ = 282567120.

The previous prime is 649905379. The next prime is 649905409. The reversal of 649905388 is 883509946.

It is a happy number.

It is a super-3 number, since 3×649905388³ (a number of 27 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 320088 + ... + 322111.

It is an arithmetic number, because the mean of its divisors is an integer number (53944800).

Almost surely, 2^649905388 is an apocalyptic number.

It is an amenable number.

649905388 is a deficient number, since it is larger than the sum of its proper divisors (644769812).

649905388 is a wasteful number, since it uses less digits than its factorization.

649905388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 642237 (or 642235 counting only the distinct ones).

The product of its (nonzero) digits is 1866240, while the sum is 52.

The square root of 649905388 is about 25493.2420064612. The cubic root of 649905388 is about 866.1970742686.

The spelling of 649905388 in words is "six hundred forty-nine million, nine hundred five thousand, three hundred eighty-eight".