220660640 has 24 divisors (see below), whose sum is σ = 521311140. Its totient is φ = 88264192.

The previous prime is 220660633. The next prime is 220660651. The reversal of 220660640 is 46066022.

It can be written as a sum of positive squares in 2 ways, for example, as 212343184 + 8317456 = 14572^2 + 2884^2 .

It is a super-2 number, since 2×220660640² = 97382236090419200, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 689405 + ... + 689724.

Almost surely, 2^220660640 is an apocalyptic number.

220660640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

220660640 is an abundant number, since it is smaller than the sum of its proper divisors (300650500).

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

220660640 is a wasteful number, since it uses less digits than its factorization.

220660640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1379144 (or 1379136 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 26.

The square root of 220660640 is about 14854.6504502799. The cubic root of 220660640 is about 604.2847362958.

The spelling of 220660640 in words is "two hundred twenty million, six hundred sixty thousand, six hundred forty".