21867542 has 16 divisors (see below), whose sum is σ = 34842960. Its totient is φ = 10257408.

The previous prime is 21867541. The next prime is 21867551. The reversal of 21867542 is 24576812.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21867541) 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, 12038 + ... + 13734.

It is an arithmetic number, because the mean of its divisors is an integer number (2177685).

Almost surely, 2^21867542 is an apocalyptic number.

21867542 is a deficient number, since it is larger than the sum of its proper divisors (12975418).

21867542 is a wasteful number, since it uses less digits than its factorization.

21867542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2095.

The product of its digits is 26880, while the sum is 35.

The square root of 21867542 is about 4676.2743717622. The cubic root of 21867542 is about 279.6404483566.

The spelling of 21867542 in words is "twenty-one million, eight hundred sixty-seven thousand, five hundred forty-two".