21301125551 has 2 divisors, whose sum is σ = 21301125552. Its totient is φ = 21301125550.

The previous prime is 21301125541. The next prime is 21301125557. The reversal of 21301125551 is 15552110312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21301125551 - 2⁶ = 21301125487 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21301125551.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21301125557) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10650562775 + 10650562776.

It is an arithmetic number, because the mean of its divisors is an integer number (10650562776).

Almost surely, 2^21301125551 is an apocalyptic number.

21301125551 is a deficient number, since it is larger than the sum of its proper divisors (1).

21301125551 is an equidigital number, since it uses as much as digits as its factorization.

21301125551 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1500, while the sum is 26.

Adding to 21301125551 its reverse (15552110312), we get a palindrome (36853235863).

The spelling of 21301125551 in words is "twenty-one billion, three hundred one million, one hundred twenty-five thousand, five hundred fifty-one".