21101301251 has 2 divisors, whose sum is σ = 21101301252. Its totient is φ = 21101301250.

The previous prime is 21101301239. The next prime is 21101301307. The reversal of 21101301251 is 15210310112.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21101301251 is a prime.

It is not a weakly prime, because it can be changed into another prime (21101301211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10550650625 + 10550650626.

It is an arithmetic number, because the mean of its divisors is an integer number (10550650626).

Almost surely, 2^21101301251 is an apocalyptic number.

21101301251 is a deficient number, since it is larger than the sum of its proper divisors (1).

21101301251 is an equidigital number, since it uses as much as digits as its factorization.

21101301251 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 60, while the sum is 17.

Adding to 21101301251 its reverse (15210310112), we get a palindrome (36311611363).

The spelling of 21101301251 in words is "twenty-one billion, one hundred one million, three hundred one thousand, two hundred fifty-one".