221660064 has 60 divisors (see below), whose sum is σ = 651903714. Its totient is φ = 73885824.

The previous prime is 221660057. The next prime is 221660071. The reversal of 221660064 is 460066122.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (221660057) and next prime (221660071).

It can be written as a sum of positive squares in only one way, i.e., 156050064 + 65610000 = 12492^2 + 8100^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 40167 + ... + 45350.

Almost surely, 2^221660064 is an apocalyptic number.

221660064 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

221660064 is an abundant number, since it is smaller than the sum of its proper divisors (430243650).

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

221660064 is an equidigital number, since it uses as much as digits as its factorization.

221660064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85539 (or 85522 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 221660064 is about 14888.2525502491. The cubic root of 221660064 is about 605.1956783427.

The spelling of 221660064 in words is "two hundred twenty-one million, six hundred sixty thousand, sixty-four".