21111151015151 has 4 divisors (see below), whose sum is σ = 21111165807600. Its totient is φ = 21111136222704.

The previous prime is 21111151015147. The next prime is 21111151015219. The reversal of 21111151015151 is 15151015111112.

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 21111151015151 - 2² = 21111151015147 is a prime.

It is a super-2 number, since 2×21111151015151² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21111151015151.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21111151015121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4995806 + ... + 8196363.

It is an arithmetic number, because the mean of its divisors is an integer number (5277791451900).

Almost surely, 2^{21111151015151} is an apocalyptic number.

21111151015151 is a deficient number, since it is larger than the sum of its proper divisors (14792449).

21111151015151 is a wasteful number, since it uses less digits than its factorization.

21111151015151 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14792448.

The product of its (nonzero) digits is 250, while the sum is 26.

Adding to 21111151015151 its reverse (15151015111112), we get a palindrome (36262166126263).

The spelling of 21111151015151 in words is "twenty-one trillion, one hundred eleven billion, one hundred fifty-one million, fifteen thousand, one hundred fifty-one".