21142051 has 16 divisors (see below), whose sum is σ = 24958720. Its totient is φ = 17534880.

The previous prime is 21142021. The next prime is 21142061. The reversal of 21142051 is 15024112.

It is a cyclic number.

It is not a de Polignac number, because 21142051 - 2⁹ = 21141539 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21142021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28240 + ... + 28978.

It is an arithmetic number, because the mean of its divisors is an integer number (1559920).

Almost surely, 2^21142051 is an apocalyptic number.

21142051 is a deficient number, since it is larger than the sum of its proper divisors (3816669).

21142051 is an equidigital number, since it uses as much as digits as its factorization.

21142051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 874.

The product of its (nonzero) digits is 80, while the sum is 16.

The square root of 21142051 is about 4598.0486078335. The cubic root of 21142051 is about 276.5130963345.

Adding to 21142051 its reverse (15024112), we get a palindrome (36166163).

The spelling of 21142051 in words is "twenty-one million, one hundred forty-two thousand, fifty-one".