64646220 has 96 divisors (see below), whose sum is σ = 191056320. Its totient is φ = 16307200.

The previous prime is 64646209. The next prime is 64646221. The reversal of 64646220 is 2264646.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (64646221) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 91870 + ... + 92570.

It is an arithmetic number, because the mean of its divisors is an integer number (1990170).

Almost surely, 2^64646220 is an apocalyptic number.

64646220 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 64646220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (95528160).

64646220 is an abundant number, since it is smaller than the sum of its proper divisors (126410100).

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

64646220 is a wasteful number, since it uses less digits than its factorization.

64646220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 795 (or 793 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 30.

The square root of 64646220 is about 8040.2873082994. The cubic root of 64646220 is about 401.3417856620.

The spelling of 64646220 in words is "sixty-four million, six hundred forty-six thousand, two hundred twenty".