649321920 has 560 divisors, whose sum is σ = 2602309248. Its totient is φ = 152616960.

The previous prime is 649321891. The next prime is 649321927. The reversal of 649321920 is 29123946.

649321920 is a `hidden beast` number, since 649 + 3 + 2 + 1 + 9 + 2 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (649321927) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 13815337 + ... + 13815383.

Almost surely, 2^649321920 is an apocalyptic number.

649321920 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 649321920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1301154624).

649321920 is an abundant number, since it is smaller than the sum of its proper divisors (1952987328).

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

649321920 is a wasteful number, since it uses less digits than its factorization.

649321920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130 (or 111 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 36.

The square root of 649321920 is about 25481.7958550805. The cubic root of 649321920 is about 865.9377803243.

The spelling of 649321920 in words is "six hundred forty-nine million, three hundred twenty-one thousand, nine hundred twenty".