21270258 has 12 divisors (see below), whose sum is σ = 46085598. Its totient is φ = 7090080.

The previous prime is 21270233. The next prime is 21270269. The reversal of 21270258 is 85207212.

It can be written as a sum of positive squares in only one way, i.e., 15233409 + 6036849 = 3903^2 + 2457^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 590823 + ... + 590858.

Almost surely, 2^21270258 is an apocalyptic number.

21270258 is an abundant number, since it is smaller than the sum of its proper divisors (24815340).

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

21270258 is a wasteful number, since it uses less digits than its factorization.

21270258 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1181689 (or 1181686 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

The square root of 21270258 is about 4611.9689938247. The cubic root of 21270258 is about 277.0709024492.

It can be divided in two parts, 21270 and 258, that added together give a triangular number (21528 = T₂₀₇).

The spelling of 21270258 in words is "twenty-one million, two hundred seventy thousand, two hundred fifty-eight".