21958368 has 24 divisors (see below), whose sum is σ = 57640968. Its totient is φ = 7319424.

The previous prime is 21958367. The next prime is 21958369. The reversal of 21958368 is 86385912.

It is an interprime number because it is at equal distance from previous prime (21958367) and next prime (21958369).

It is a tau number, because it is divible by the number of its divisors (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21958361) 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, 114271 + ... + 114462.

It is an arithmetic number, because the mean of its divisors is an integer number (2401707).

Almost surely, 2^21958368 is an apocalyptic number.

It is an amenable number.

21958368 is an abundant number, since it is smaller than the sum of its proper divisors (35682600).

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

21958368 is a wasteful number, since it uses less digits than its factorization.

21958368 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 228746 (or 228738 counting only the distinct ones).

The product of its digits is 103680, while the sum is 42.

The square root of 21958368 is about 4685.9756721520. The cubic root of 21958368 is about 280.0270722123.

The spelling of 21958368 in words is "twenty-one million, nine hundred fifty-eight thousand, three hundred sixty-eight".