22138640 has 40 divisors (see below), whose sum is σ = 51901440. Its totient is φ = 8781696.

The previous prime is 22138631. The next prime is 22138643. The reversal of 22138640 is 4683122.

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (22138643) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 9071 + ... + 11249.

It is an arithmetic number, because the mean of its divisors is an integer number (1297536).

Almost surely, 2^22138640 is an apocalyptic number.

22138640 is a gapful number since it is divisible by the number (20) 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 22138640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25950720).

22138640 is an abundant number, since it is smaller than the sum of its proper divisors (29762800).

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

22138640 is a wasteful number, since it uses less digits than its factorization.

22138640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2319 (or 2313 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 26.

The square root of 22138640 is about 4705.1716227997. The cubic root of 22138640 is about 280.7912990434.

The spelling of 22138640 in words is "twenty-two million, one hundred thirty-eight thousand, six hundred forty".