64900891440 has 640 divisors, whose sum is σ = 283321866240. Its totient is φ = 13262745600.

The previous prime is 64900891421. The next prime is 64900891453. The reversal of 64900891440 is 4419800946.

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

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 10142322 + ... + 10148718.

It is an arithmetic number, because the mean of its divisors is an integer number (442690416).

Almost surely, 2^64900891440 is an apocalyptic number.

64900891440 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 64900891440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (141660933120).

64900891440 is an abundant number, since it is smaller than the sum of its proper divisors (218420974800).

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

64900891440 is a wasteful number, since it uses less digits than its factorization.

64900891440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6498 (or 6486 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 45.

The spelling of 64900891440 in words is "sixty-four billion, nine hundred million, eight hundred ninety-one thousand, four hundred forty".