22187988 has 36 divisors (see below), whose sum is σ = 56929600. Its totient is φ = 7284816.

The previous prime is 22187981. The next prime is 22187989. The reversal of 22187988 is 88978122.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×22187988² = 984613622976288, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22187981) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 2188 + ... + 7011.

Almost surely, 2^22187988 is an apocalyptic number.

It is an amenable number.

22187988 is an abundant number, since it is smaller than the sum of its proper divisors (34741612).

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

22187988 is a wasteful number, since it uses less digits than its factorization.

22187988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9276 (or 9271 counting only the distinct ones).

The product of its digits is 129024, while the sum is 45.

The square root of 22187988 is about 4710.4127207709. The cubic root of 22187988 is about 280.9997762607. Note that the first 3 decimals are identical.

It can be divided in two parts, 221 and 87988, that added together give a square (88209 = 297²).

The spelling of 22187988 in words is "twenty-two million, one hundred eighty-seven thousand, nine hundred eighty-eight".