21214025126251 has 4 divisors (see below), whose sum is σ = 21217831703712. Its totient is φ = 21210218548792.

The previous prime is 21214025126207. The next prime is 21214025126299. The reversal of 21214025126251 is 15262152041212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21214025126251 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21214025126551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1903280371 + ... + 1903291516.

It is an arithmetic number, because the mean of its divisors is an integer number (5304457925928).

Almost surely, 2^{21214025126251} is an apocalyptic number.

21214025126251 is a deficient number, since it is larger than the sum of its proper divisors (3806577461).

21214025126251 is an equidigital number, since it uses as much as digits as its factorization.

21214025126251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3806577460.

The product of its (nonzero) digits is 19200, while the sum is 34.

Adding to 21214025126251 its reverse (15262152041212), we get a palindrome (36476177167463).

The spelling of 21214025126251 in words is "twenty-one trillion, two hundred fourteen billion, twenty-five million, one hundred twenty-six thousand, two hundred fifty-one".