64999620 has 144 divisors (see below), whose sum is σ = 228533760. Its totient is φ = 14646528.

The previous prime is 64999601. The next prime is 64999663. The reversal of 64999620 is 2699946.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 99214 + ... + 99866.

It is an arithmetic number, because the mean of its divisors is an integer number (1587040).

Almost surely, 2^64999620 is an apocalyptic number.

64999620 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 64999620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (114266880).

64999620 is an abundant number, since it is smaller than the sum of its proper divisors (163534140).

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

64999620 is a wasteful number, since it uses less digits than its factorization.

64999620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 754 (or 749 counting only the distinct ones).

The product of its (nonzero) digits is 209952, while the sum is 45.

The square root of 64999620 is about 8062.2341816645. The cubic root of 64999620 is about 402.0717923313.

The spelling of 64999620 in words is "sixty-four million, nine hundred ninety-nine thousand, six hundred twenty".