22399540 has 24 divisors (see below), whose sum is σ = 49806792. Its totient is φ = 8432640.

The previous prime is 22399471. The next prime is 22399547. The reversal of 22399540 is 4599322.

22399540 = 1215² + 1216² + ... + 1229².

It can be written as a sum of positive squares in 4 ways, for example, as 5143824 + 17255716 = 2268^2 + 4154^2 .

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a junction number, because it is equal to n+sod(n) for n = 22399496 and 22399505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22399547) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32601 + ... + 33280.

It is an arithmetic number, because the mean of its divisors is an integer number (2075283).

Almost surely, 2^22399540 is an apocalyptic number.

22399540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

22399540 is an abundant number, since it is smaller than the sum of its proper divisors (27407252).

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

22399540 is a wasteful number, since it uses less digits than its factorization.

22399540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65907 (or 65905 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 34.

The square root of 22399540 is about 4732.8152298606. The cubic root of 22399540 is about 281.8900196519.

The spelling of 22399540 in words is "twenty-two million, three hundred ninety-nine thousand, five hundred forty".