21202200251 has 2 divisors, whose sum is σ = 21202200252. Its totient is φ = 21202200250.

The previous prime is 21202200247. The next prime is 21202200277. The reversal of 21202200251 is 15200220212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21202200251 - 2² = 21202200247 is a prime.

It is not a weakly prime, because it can be changed into another prime (21202200281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10601100125 + 10601100126.

It is an arithmetic number, because the mean of its divisors is an integer number (10601100126).

Almost surely, 2^21202200251 is an apocalyptic number.

21202200251 is a deficient number, since it is larger than the sum of its proper divisors (1).

21202200251 is an equidigital number, since it uses as much as digits as its factorization.

21202200251 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 160, while the sum is 17.

Adding to 21202200251 its reverse (15200220212), we get a palindrome (36402420463).

The spelling of 21202200251 in words is "twenty-one billion, two hundred two million, two hundred thousand, two hundred fifty-one".