22279640 has 64 divisors (see below), whose sum is σ = 53300160. Its totient is φ = 8363520.

The previous prime is 22279613. The next prime is 22279643. The reversal of 22279640 is 4697222.

22279640 = T₈₂₄ + T₈₂₅ + ... + T₈₈₄.

It is a junction number, because it is equal to n+sod(n) for n = 22279597 and 22279606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22279643) 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, 55922 + ... + 56318.

It is an arithmetic number, because the mean of its divisors is an integer number (832815).

Almost surely, 2^22279640 is an apocalyptic number.

22279640 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 22279640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26650080).

22279640 is an abundant number, since it is smaller than the sum of its proper divisors (31020520).

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

22279640 is a wasteful number, since it uses less digits than its factorization.

22279640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 492 (or 488 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 32.

The square root of 22279640 is about 4720.1313541045. The cubic root of 22279640 is about 281.3861536656.

The spelling of 22279640 in words is "twenty-two million, two hundred seventy-nine thousand, six hundred forty".