20228688 has 30 divisors (see below), whose sum is σ = 56612634. Its totient is φ = 6742848.

The previous prime is 20228683. The next prime is 20228693. The reversal of 20228688 is 88682202.

It is an interprime number because it is at equal distance from previous prime (20228683) and next prime (20228693).

It can be written as a sum of positive squares in only one way, i.e., 12873744 + 7354944 = 3588^2 + 2712^2 .

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20228683) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 70095 + ... + 70382.

Almost surely, 2^20228688 is an apocalyptic number.

It is an amenable number.

20228688 is an abundant number, since it is smaller than the sum of its proper divisors (36383946).

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

20228688 is a wasteful number, since it uses less digits than its factorization.

20228688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140491 (or 140482 counting only the distinct ones).

The product of its (nonzero) digits is 24576, while the sum is 36.

The square root of 20228688 is about 4497.6313766248. The cubic root of 20228688 is about 272.4724344363.

The spelling of 20228688 in words is "twenty million, two hundred twenty-eight thousand, six hundred eighty-eight".