22640 has 20 divisors (see below), whose sum is σ = 52824. Its totient is φ = 9024.

The previous prime is 22639. The next prime is 22643. The reversal of 22640 is 4622.

22640 = T₄₅ + T₄₆ + ... + T₆₀.

It is a tau number, because it is divible by the number of its divisors (20).

It is a plaindrome in base 12.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22643) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 62 + ... + 221.

2²²⁶⁴⁰ is an apocalyptic number.

22640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

22640 is an abundant number, since it is smaller than the sum of its proper divisors (30184).

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26412).

22640 is a wasteful number, since it uses less digits than its factorization.

22640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 296 (or 290 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 14.

The square root of 22640 is about 150.4659429904. The cubic root of 22640 is about 28.2895131934.

The spelling of 22640 in words is "twenty-two thousand, six hundred forty".