21168051 has 4 divisors (see below), whose sum is σ = 28224072. Its totient is φ = 14112032.

The previous prime is 21168031. The next prime is 21168053. The reversal of 21168051 is 15086112.

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 21168051 - 2⁶ = 21167987 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21168053) 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, 3528006 + ... + 3528011.

It is an arithmetic number, because the mean of its divisors is an integer number (7056018).

Almost surely, 2^21168051 is an apocalyptic number.

21168051 is a deficient number, since it is larger than the sum of its proper divisors (7056021).

21168051 is an equidigital number, since it uses as much as digits as its factorization.

21168051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7056020.

The product of its (nonzero) digits is 480, while the sum is 24.

The square root of 21168051 is about 4600.8750254707. The cubic root of 21168051 is about 276.6263996815.

The spelling of 21168051 in words is "twenty-one million, one hundred sixty-eight thousand, fifty-one".