21983542 has 16 divisors (see below), whose sum is σ = 37856160. Its totient is φ = 9379008.

The previous prime is 21983531. The next prime is 21983569. The reversal of 21983542 is 24538912.

It is a super-2 number, since 2×21983542² = 966552237731528, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21983498 and 21983507.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 223 + ... + 6634.

It is an arithmetic number, because the mean of its divisors is an integer number (2366010).

Almost surely, 2^21983542 is an apocalyptic number.

21983542 is a deficient number, since it is larger than the sum of its proper divisors (15872618).

21983542 is a wasteful number, since it uses less digits than its factorization.

21983542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7095.

The product of its digits is 17280, while the sum is 34.

The square root of 21983542 is about 4688.6610028877. The cubic root of 21983542 is about 280.1340429629.

The spelling of 21983542 in words is "twenty-one million, nine hundred eighty-three thousand, five hundred forty-two".