21355254 has 12 divisors (see below), whose sum is σ = 46269756. Its totient is φ = 7118412.

The previous prime is 21355241. The next prime is 21355261. The reversal of 21355254 is 45255312.

It is a happy number.

21355254 is a `hidden beast` number, since 2 + 135 + 525 + 4 = 666.

It is a congruent 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, 593184 + ... + 593219.

It is an arithmetic number, because the mean of its divisors is an integer number (3855813).

Almost surely, 2^21355254 is an apocalyptic number.

21355254 is an abundant number, since it is smaller than the sum of its proper divisors (24914502).

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

21355254 is a wasteful number, since it uses less digits than its factorization.

21355254 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1186411 (or 1186408 counting only the distinct ones).

The product of its digits is 6000, while the sum is 27.

The square root of 21355254 is about 4621.1745260269. The cubic root of 21355254 is about 277.4394706062.

It can be divided in two parts, 21355 and 254, that added together give a square (21609 = 147²).

The spelling of 21355254 in words is "twenty-one million, three hundred fifty-five thousand, two hundred fifty-four".