21151231123151 has 4 divisors (see below), whose sum is σ = 21151423041312. Its totient is φ = 21151039204992.

The previous prime is 21151231123147. The next prime is 21151231123193. The reversal of 21151231123151 is 15132113215112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21151231123151 - 2² = 21151231123147 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21151237123151) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 95793671 + ... + 96014216.

It is an arithmetic number, because the mean of its divisors is an integer number (5287855760328).

Almost surely, 2^{21151231123151} is an apocalyptic number.

21151231123151 is a deficient number, since it is larger than the sum of its proper divisors (191918161).

21151231123151 is a wasteful number, since it uses less digits than its factorization.

21151231123151 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 191918160.

The product of its digits is 1800, while the sum is 29.

Adding to 21151231123151 its reverse (15132113215112), we get a palindrome (36283344338263).

The spelling of 21151231123151 in words is "twenty-one trillion, one hundred fifty-one billion, two hundred thirty-one million, one hundred twenty-three thousand, one hundred fifty-one".