64986649920 has 560 divisors, whose sum is σ = 238545014400. Its totient is φ = 16784216064.

The previous prime is 64986649841. The next prime is 64986649939. The reversal of 64986649920 is 2994668946.

64986649920 is a `hidden beast` number, since 6 + 49 + 86 + 6 + 499 + 20 = 666.

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 79 ways as a sum of consecutive naturals, for example, 221797294 + ... + 221797586.

It is an arithmetic number, because the mean of its divisors is an integer number (425973240).

Almost surely, 2^64986649920 is an apocalyptic number.

64986649920 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 64986649920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (119272507200).

64986649920 is an abundant number, since it is smaller than the sum of its proper divisors (173558364480).

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

64986649920 is a wasteful number, since it uses less digits than its factorization.

64986649920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 564 (or 545 counting only the distinct ones).

The product of its (nonzero) digits is 40310784, while the sum is 63.

The spelling of 64986649920 in words is "sixty-four billion, nine hundred eighty-six million, six hundred forty-nine thousand, nine hundred twenty".