21415842 has 36 divisors (see below), whose sum is σ = 53978886. Its totient is φ = 6118560.

The previous prime is 21415841. The next prime is 21415847. The reversal of 21415842 is 24851412.

It can be written as a sum of positive squares in only one way, i.e., 12895281 + 8520561 = 3591^2 + 2919^2 .

It is not an unprimeable number, because it can be changed into a prime (21415841) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 11259 + ... + 13022.

Almost surely, 2^21415842 is an apocalyptic number.

21415842 is an abundant number, since it is smaller than the sum of its proper divisors (32563044).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21415842 is a wasteful number, since it uses less digits than its factorization.

21415842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24303 (or 24293 counting only the distinct ones).

The product of its digits is 2560, while the sum is 27.

The square root of 21415842 is about 4627.7253591803. The cubic root of 21415842 is about 277.7016017371.

The spelling of 21415842 in words is "twenty-one million, four hundred fifteen thousand, eight hundred forty-two".