21642874 has 16 divisors (see below), whose sum is σ = 36637920. Its totient is φ = 9498160.

The previous prime is 21642871. The next prime is 21642883. The reversal of 21642874 is 47824612.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21642871) 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, 16324 + ... + 17599.

It is an arithmetic number, because the mean of its divisors is an integer number (2289870).

Almost surely, 2^21642874 is an apocalyptic number.

21642874 is a deficient number, since it is larger than the sum of its proper divisors (14995046).

21642874 is a wasteful number, since it uses less digits than its factorization.

21642874 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33965.

The product of its digits is 21504, while the sum is 34.

The square root of 21642874 is about 4652.1902368669. The cubic root of 21642874 is about 278.6794707175.

The spelling of 21642874 in words is "twenty-one million, six hundred forty-two thousand, eight hundred seventy-four".