21003042 has 16 divisors (see below), whose sum is σ = 42164352. Its totient is φ = 6974640.

The previous prime is 21003011. The next prime is 21003053. The reversal of 21003042 is 24030012.

It is a super-2 number, since 2×21003042² = 882255546507528, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4833 + ... + 8084.

It is an arithmetic number, because the mean of its divisors is an integer number (2635272).

Almost surely, 2^21003042 is an apocalyptic number.

21003042 is an abundant number, since it is smaller than the sum of its proper divisors (21161310).

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

21003042 is a wasteful number, since it uses less digits than its factorization.

21003042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13193.

The product of its (nonzero) digits is 48, while the sum is 12.

The square root of 21003042 is about 4582.9075923479. The cubic root of 21003042 is about 275.9057386574.

Adding to 21003042 its reverse (24030012), we get a palindrome (45033054).

The spelling of 21003042 in words is "twenty-one million, three thousand, forty-two".