21402258 has 16 divisors (see below), whose sum is σ = 42879936. Its totient is φ = 7121520.

The previous prime is 21402257. The next prime is 21402263. The reversal of 21402258 is 85220412.

It is not an unprimeable number, because it can be changed into a prime (21402253) 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, 960 + ... + 6612.

It is an arithmetic number, because the mean of its divisors is an integer number (2679996).

Almost surely, 2^21402258 is an apocalyptic number.

21402258 is an abundant number, since it is smaller than the sum of its proper divisors (21477678).

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

21402258 is a wasteful number, since it uses less digits than its factorization.

21402258 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6289.

The product of its (nonzero) digits is 1280, while the sum is 24.

The square root of 21402258 is about 4626.2574506830. The cubic root of 21402258 is about 277.6428742395.

The spelling of 21402258 in words is "twenty-one million, four hundred two thousand, two hundred fifty-eight".