21459842 has 4 divisors (see below), whose sum is σ = 32189766. Its totient is φ = 10729920.

The previous prime is 21459833. The next prime is 21459853. The reversal of 21459842 is 24895412.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 12453841 + 9006001 = 3529^2 + 3001^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5364959 + ... + 5364962.

Almost surely, 2^21459842 is an apocalyptic number.

21459842 is a deficient number, since it is larger than the sum of its proper divisors (10729924).

21459842 is a wasteful number, since it uses less digits than its factorization.

21459842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10729923.

The product of its digits is 23040, while the sum is 35.

The square root of 21459842 is about 4632.4768752796. The cubic root of 21459842 is about 277.8916559332.

The spelling of 21459842 in words is "twenty-one million, four hundred fifty-nine thousand, eight hundred forty-two".