21132051 has 4 divisors (see below), whose sum is σ = 28176072. Its totient is φ = 14088032.

The previous prime is 21132011. The next prime is 21132061. The reversal of 21132051 is 15023112.

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 21132051 - 2¹³ = 21123859 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21132051.

It is not an unprimeable number, because it can be changed into a prime (21132011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3522006 + ... + 3522011.

It is an arithmetic number, because the mean of its divisors is an integer number (7044018).

Almost surely, 2^21132051 is an apocalyptic number.

21132051 is a deficient number, since it is larger than the sum of its proper divisors (7044021).

21132051 is an equidigital number, since it uses as much as digits as its factorization.

21132051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7044020.

The product of its (nonzero) digits is 60, while the sum is 15.

The square root of 21132051 is about 4596.9610613970. The cubic root of 21132051 is about 276.4694933899.

Adding to 21132051 its reverse (15023112), we get a palindrome (36155163).

The spelling of 21132051 in words is "twenty-one million, one hundred thirty-two thousand, fifty-one".