220428864 has 140 divisors (see below), whose sum is σ = 661457148. Its totient is φ = 72576000.

The previous prime is 220428821. The next prime is 220428877. The reversal of 220428864 is 468824022.

It is a happy number.

220428864 is a `hidden beast` number, since 220 + 428 + 8 + 6 + 4 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 95883264 + 124545600 = 9792^2 + 11160^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 523374 + ... + 523794.

Almost surely, 2^220428864 is an apocalyptic number.

220428864 is a gapful number since it is divisible by the number (24) 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 220428864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (330728574).

220428864 is an abundant number, since it is smaller than the sum of its proper divisors (441028284).

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

220428864 is a wasteful number, since it uses less digits than its factorization.

220428864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 546 (or 527 counting only the distinct ones).

The product of its (nonzero) digits is 49152, while the sum is 36.

The square root of 220428864 is about 14846.8469379865. The cubic root of 220428864 is about 604.0730873649.

The spelling of 220428864 in words is "two hundred twenty million, four hundred twenty-eight thousand, eight hundred sixty-four".