21330951 has 4 divisors (see below), whose sum is σ = 28441272. Its totient is φ = 14220632.

The previous prime is 21330949. The next prime is 21330983. The reversal of 21330951 is 15903312.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21330951 - 2¹ = 21330949 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21330941) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3555156 + ... + 3555161.

It is an arithmetic number, because the mean of its divisors is an integer number (7110318).

Almost surely, 2^21330951 is an apocalyptic number.

21330951 is a deficient number, since it is larger than the sum of its proper divisors (7110321).

21330951 is an equidigital number, since it uses as much as digits as its factorization.

21330951 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7110320.

The product of its (nonzero) digits is 810, while the sum is 24.

The square root of 21330951 is about 4618.5442511683. The cubic root of 21330951 is about 277.3341854955.

The spelling of 21330951 in words is "twenty-one million, three hundred thirty thousand, nine hundred fifty-one".