649237680 has 480 divisors, whose sum is σ = 2790488064. Its totient is φ = 136608768.

The previous prime is 649237663. The next prime is 649237697. The reversal of 649237680 is 86732946.

It is an interprime number because it is at equal distance from previous prime (649237663) and next prime (649237697).

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 (13) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1768857 + ... + 1769223.

Almost surely, 2^649237680 is an apocalyptic number.

649237680 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 649237680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1395244032).

649237680 is an abundant number, since it is smaller than the sum of its proper divisors (2141250384).

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

649237680 is a wasteful number, since it uses less digits than its factorization.

649237680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 415 (or 397 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 45.

The square root of 649237680 is about 25480.1428567424. The cubic root of 649237680 is about 865.9003311273.

The spelling of 649237680 in words is "six hundred forty-nine million, two hundred thirty-seven thousand, six hundred eighty".