64433720988 has 144 divisors (see below), whose sum is σ = 203747334336. Its totient is φ = 16714874880.

The previous prime is 64433720983. The next prime is 64433720993. The reversal of 64433720988 is 88902733446.

64433720988 is a `hidden beast` number, since 64 + 433 + 72 + 0 + 9 + 88 = 666.

It is an interprime number because it is at equal distance from previous prime (64433720983) and next prime (64433720993).

It is a super-2 number, since 2×64433720988² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64433720983) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 38620 + ... + 361052.

It is an arithmetic number, because the mean of its divisors is an integer number (1414912044).

Almost surely, 2^64433720988 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64433720988, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (101873667168).

64433720988 is an abundant number, since it is smaller than the sum of its proper divisors (139313613348).

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

64433720988 is a wasteful number, since it uses less digits than its factorization.

64433720988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 322524 (or 322519 counting only the distinct ones).

The product of its (nonzero) digits is 6967296, while the sum is 54.

The spelling of 64433720988 in words is "sixty-four billion, four hundred thirty-three million, seven hundred twenty thousand, nine hundred eighty-eight".