21151420231 has 2 divisors, whose sum is σ = 21151420232. Its totient is φ = 21151420230.

The previous prime is 21151420159. The next prime is 21151420271. The reversal of 21151420231 is 13202415112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21151420231 - 2³¹ = 19003936583 is a prime.

It is a super-2 number, since 2×21151420231² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21151420271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10575710115 + 10575710116.

It is an arithmetic number, because the mean of its divisors is an integer number (10575710116).

Almost surely, 2^21151420231 is an apocalyptic number.

21151420231 is a deficient number, since it is larger than the sum of its proper divisors (1).

21151420231 is an equidigital number, since it uses as much as digits as its factorization.

21151420231 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 480, while the sum is 22.

Adding to 21151420231 its reverse (13202415112), we get a palindrome (34353835343).

The spelling of 21151420231 in words is "twenty-one billion, one hundred fifty-one million, four hundred twenty thousand, two hundred thirty-one".