21012111151 has 2 divisors, whose sum is σ = 21012111152. Its totient is φ = 21012111150.

The previous prime is 21012111149. The next prime is 21012111157. The reversal of 21012111151 is 15111121012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21012111151 - 2¹ = 21012111149 is a prime.

Together with 21012111149, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21012111157) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506055575 + 10506055576.

It is an arithmetic number, because the mean of its divisors is an integer number (10506055576).

Almost surely, 2^21012111151 is an apocalyptic number.

21012111151 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012111151 is an equidigital number, since it uses as much as digits as its factorization.

21012111151 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20, while the sum is 16.

Adding to 21012111151 its reverse (15111121012), we get a palindrome (36123232163).

The spelling of 21012111151 in words is "twenty-one billion, twelve million, one hundred eleven thousand, one hundred fifty-one".