21014251 has 4 divisors (see below), whose sum is σ = 21025312. Its totient is φ = 21003192.

The previous prime is 21014243. The next prime is 21014297. The reversal of 21014251 is 15241012.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21014251 - 2³ = 21014243 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21014351) 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, 1875 + ... + 6748.

It is an arithmetic number, because the mean of its divisors is an integer number (5256328).

Almost surely, 2^21014251 is an apocalyptic number.

21014251 is a deficient number, since it is larger than the sum of its proper divisors (11061).

21014251 is an equidigital number, since it uses as much as digits as its factorization.

21014251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11060.

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

The square root of 21014251 is about 4584.1303428240. The cubic root of 21014251 is about 275.9548121428.

Adding to 21014251 its reverse (15241012), we get a palindrome (36255263).

The spelling of 21014251 in words is "twenty-one million, fourteen thousand, two hundred fifty-one".