649249920 has 192 divisors, whose sum is σ = 2445992640. Its totient is φ = 157378560.

The previous prime is 649249897. The next prime is 649249943. The reversal of 649249920 is 29942946.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (649249897) and next prime (649249943).

It is a tau number, because it is divible by the number of its divisors (192).

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 (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 58237 + ... + 68483.

It is an arithmetic number, because the mean of its divisors is an integer number (12739545).

Almost surely, 2^649249920 is an apocalyptic number.

649249920 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 649249920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1222996320).

649249920 is an abundant number, since it is smaller than the sum of its proper divisors (1796742720).

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

649249920 is a wasteful number, since it uses less digits than its factorization.

649249920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10283 (or 10268 counting only the distinct ones).

The product of its (nonzero) digits is 279936, while the sum is 45.

The square root of 649249920 is about 25480.3830426467. The cubic root of 649249920 is about 865.9057726648.

The spelling of 649249920 in words is "six hundred forty-nine million, two hundred forty-nine thousand, nine hundred twenty".