21232051 has 4 divisors (see below), whose sum is σ = 21290272. Its totient is φ = 21173832.

The previous prime is 21232049. The next prime is 21232073. The reversal of 21232051 is 15023212.

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 21232051 - 2¹ = 21232049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21232091) 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, 28560 + ... + 29293.

It is an arithmetic number, because the mean of its divisors is an integer number (5322568).

Almost surely, 2^21232051 is an apocalyptic number.

21232051 is a deficient number, since it is larger than the sum of its proper divisors (58221).

21232051 is an equidigital number, since it uses as much as digits as its factorization.

21232051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58220.

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 21232051 is about 4607.8249749746. The cubic root of 21232051 is about 276.9049055166.

Adding to 21232051 its reverse (15023212), we get a palindrome (36255263).

The spelling of 21232051 in words is "twenty-one million, two hundred thirty-two thousand, fifty-one".