21255151 has 8 divisors (see below), whose sum is σ = 23484384. Its totient is φ = 19134720.

The previous prime is 21255133. The next prime is 21255161. The reversal of 21255151 is 15155212.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21255151 - 2¹¹ = 21253103 is a prime.

It is a Duffinian number.

21255151 is a modest number, since divided by 5151 gives 2125 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21255161) 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, 26790 + ... + 27571.

It is an arithmetic number, because the mean of its divisors is an integer number (2935548).

Almost surely, 2^21255151 is an apocalyptic number.

21255151 is a deficient number, since it is larger than the sum of its proper divisors (2229233).

21255151 is a wasteful number, since it uses less digits than its factorization.

21255151 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54401.

The product of its digits is 500, while the sum is 22.

The square root of 21255151 is about 4610.3308991872. The cubic root of 21255151 is about 277.0052912490.

The spelling of 21255151 in words is "twenty-one million, two hundred fifty-five thousand, one hundred fifty-one".