64923869820 has 192 divisors, whose sum is σ = 197472038400. Its totient is φ = 15883407360.

The previous prime is 64923869819. The next prime is 64923869831. The reversal of 64923869820 is 2896832946.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 6398311 + ... + 6408449.

It is an arithmetic number, because the mean of its divisors is an integer number (1028500200).

Almost surely, 2^64923869820 is an apocalyptic number.

64923869820 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 64923869820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (98736019200).

64923869820 is an abundant number, since it is smaller than the sum of its proper divisors (132548168580).

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

64923869820 is a wasteful number, since it uses less digits than its factorization.

64923869820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10348 (or 10346 counting only the distinct ones).

The product of its (nonzero) digits is 8957952, while the sum is 57.

The spelling of 64923869820 in words is "sixty-four billion, nine hundred twenty-three million, eight hundred sixty-nine thousand, eight hundred twenty".