21075642 has 24 divisors (see below), whose sum is σ = 52187616. Its totient is φ = 6021576.

The previous prime is 21075641. The next prime is 21075653. The reversal of 21075642 is 24657012.

21075642 is a `hidden beast` number, since 2 + 10 + 7 + 5 + 642 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21075641) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 83508 + ... + 83759.

It is an arithmetic number, because the mean of its divisors is an integer number (2174484).

Almost surely, 2^21075642 is an apocalyptic number.

21075642 is an abundant number, since it is smaller than the sum of its proper divisors (31111974).

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

21075642 is a wasteful number, since it uses less digits than its factorization.

21075642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167282 (or 167279 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 27.

The square root of 21075642 is about 4590.8214951139. The cubic root of 21075642 is about 276.2232755349.

The spelling of 21075642 in words is "twenty-one million, seventy-five thousand, six hundred forty-two".