21003258 has 16 divisors (see below), whose sum is σ = 42068160. Its totient is φ = 6990816.

The previous prime is 21003247. The next prime is 21003259. The reversal of 21003258 is 85230012.

It is a super-2 number, since 2×21003258² = 882273693229128, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21003259) 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, 2691 + ... + 7017.

It is an arithmetic number, because the mean of its divisors is an integer number (2629260).

Almost surely, 2^21003258 is an apocalyptic number.

21003258 is an abundant number, since it is smaller than the sum of its proper divisors (21064902).

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

21003258 is a wasteful number, since it uses less digits than its factorization.

21003258 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5141.

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 21003258 is about 4582.9311581127. The cubic root of 21003258 is about 275.9066844797.

The spelling of 21003258 in words is "twenty-one million, three thousand, two hundred fifty-eight".