23188428 has 18 divisors (see below), whose sum is σ = 58615284. Its totient is φ = 7729464.

The previous prime is 23188351. The next prime is 23188433. The reversal of 23188428 is 82488132.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-2 number, since 2×23188428² = 1075406386222368, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 644123 = 23188428 / (2 + 3 + 1 + 8 + 8 + 4 + 2 + 8).

It is a junction number, because it is equal to n+sod(n) for n = 23188392 and 23188401.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 322026 + ... + 322097.

Almost surely, 2^23188428 is an apocalyptic number.

It is an amenable number.

23188428 is an abundant number, since it is smaller than the sum of its proper divisors (35426856).

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

23188428 is a wasteful number, since it uses less digits than its factorization.

23188428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 644133 (or 644128 counting only the distinct ones).

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

The square root of 23188428 is about 4815.4364288193. The cubic root of 23188428 is about 285.1612015096.

The spelling of 23188428 in words is "twenty-three million, one hundred eighty-eight thousand, four hundred twenty-eight".