64551997440 has 1248 divisors, whose sum is σ = 283364040960. Its totient is φ = 13759414272.

The previous prime is 64551997429. The next prime is 64551997453. The reversal of 64551997440 is 4479915546.

64551997440 is a `hidden beast` number, since 6 + 4 + 5 + 5 + 199 + 7 + 440 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

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, 592220106 + ... + 592220214.

It is an arithmetic number, because the mean of its divisors is an integer number (227054520).

Almost surely, 2^64551997440 is an apocalyptic number.

64551997440 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 64551997440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (141682020480).

64551997440 is an abundant number, since it is smaller than the sum of its proper divisors (218812043520).

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

64551997440 is a wasteful number, since it uses less digits than its factorization.

64551997440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 177 (or 143 counting only the distinct ones).

The product of its (nonzero) digits is 5443200, while the sum is 54.

The spelling of 64551997440 in words is "sixty-four billion, five hundred fifty-one million, nine hundred ninety-seven thousand, four hundred forty".