649963440 has 600 divisors, whose sum is σ = 2770938720. Its totient is φ = 140507136.

The previous prime is 649963421. The next prime is 649963459. The reversal of 649963440 is 44369946.

It is a happy number.

649963440 is a `hidden beast` number, since 6 + 4 + 9 + 9 + 634 + 4 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (649963421) and next prime (649963459).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 7302916 + ... + 7303004.

Almost surely, 2^649963440 is an apocalyptic number.

649963440 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 649963440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1385469360).

649963440 is an abundant number, since it is smaller than the sum of its proper divisors (2120975280).

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

649963440 is a wasteful number, since it uses less digits than its factorization.

649963440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 151 (or 129 counting only the distinct ones).

The product of its (nonzero) digits is 559872, while the sum is 45.

The square root of 649963440 is about 25494.3805572914. The cubic root of 649963440 is about 866.2228641637. Note that the first 3 decimals are identical.

Adding to 649963440 its sum of digits (45), we get a triangular number (649963485 = T₃₆₀₅₄).

The spelling of 649963440 in words is "six hundred forty-nine million, nine hundred sixty-three thousand, four hundred forty".