649990000 has 200 divisors, whose sum is σ = 1812919680. Its totient is φ = 223200000.

The previous prime is 649989997. The next prime is 649990009. The reversal of 649990000 is 99946.

It is a tau number, because it is divible by the number of its divisors (200).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (649990009) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 2089845 + ... + 2090155.

Almost surely, 2^649990000 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 649990000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (906459840).

649990000 is an abundant number, since it is smaller than the sum of its proper divisors (1162929680).

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

649990000 is a wasteful number, since it uses less digits than its factorization.

649990000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 369 (or 348 counting only the distinct ones).

The product of its (nonzero) digits is 17496, while the sum is 37.

The square root of 649990000 is about 25494.9014510745. The cubic root of 649990000 is about 866.2346630663.

The spelling of 649990000 in words is "six hundred forty-nine million, nine hundred ninety thousand".