22155640 has 64 divisors (see below), whose sum is σ = 54250560. Its totient is φ = 8094720.

The previous prime is 22155619. The next prime is 22155649. The reversal of 22155640 is 4655122.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22155649) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 71085 + ... + 71395.

It is an arithmetic number, because the mean of its divisors is an integer number (847665).

Almost surely, 2^22155640 is an apocalyptic number.

22155640 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 22155640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27125280).

22155640 is an abundant number, since it is smaller than the sum of its proper divisors (32094920).

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

22155640 is a wasteful number, since it uses less digits than its factorization.

22155640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 472 (or 468 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 25.

The square root of 22155640 is about 4706.9777989704. The cubic root of 22155640 is about 280.8631527613.

The spelling of 22155640 in words is "twenty-two million, one hundred fifty-five thousand, six hundred forty".