21092251 has 8 divisors (see below), whose sum is σ = 22232880. Its totient is φ = 19979232.

The previous prime is 21092249. The next prime is 21092293. The reversal of 21092251 is 15229012.

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 21092251 - 2¹ = 21092249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21092051) 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, 5325 + ... + 8398.

It is an arithmetic number, because the mean of its divisors is an integer number (2779110).

Almost surely, 2^21092251 is an apocalyptic number.

21092251 is a deficient number, since it is larger than the sum of its proper divisors (1140629).

21092251 is a wasteful number, since it uses less digits than its factorization.

21092251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13805.

The product of its (nonzero) digits is 360, while the sum is 22.

The square root of 21092251 is about 4592.6300743692. The cubic root of 21092251 is about 276.2958172199.

The spelling of 21092251 in words is "twenty-one million, ninety-two thousand, two hundred fifty-one".