21968573 has 16 divisors (see below), whose sum is σ = 26256960. Its totient is φ = 18144000.

The previous prime is 21968567. The next prime is 21968603. The reversal of 21968573 is 37586912.

It is a cyclic number.

It is not a de Polignac number, because 21968573 - 2⁶ = 21968509 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21968573.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21968543) 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, 3398 + ... + 7448.

It is an arithmetic number, because the mean of its divisors is an integer number (1641060).

Almost surely, 2^21968573 is an apocalyptic number.

It is an amenable number.

21968573 is a deficient number, since it is larger than the sum of its proper divisors (4288387).

21968573 is a wasteful number, since it uses less digits than its factorization.

21968573 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4108.

The product of its digits is 90720, while the sum is 41.

The square root of 21968573 is about 4687.0644330967. The cubic root of 21968573 is about 280.0704457103.

The spelling of 21968573 in words is "twenty-one million, nine hundred sixty-eight thousand, five hundred seventy-three".