21121422151 has 4 divisors (see below), whose sum is σ = 21251001592. Its totient is φ = 20991842712.

The previous prime is 21121422131. The next prime is 21121422163. The reversal of 21121422151 is 15122412112.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21121422151 is a prime.

It is a super-2 number, since 2×21121422151² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121422131) 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, 64789476 + ... + 64789801.

It is an arithmetic number, because the mean of its divisors is an integer number (5312750398).

Almost surely, 2^21121422151 is an apocalyptic number.

21121422151 is a deficient number, since it is larger than the sum of its proper divisors (129579441).

21121422151 is a wasteful number, since it uses less digits than its factorization.

21121422151 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129579440.

The product of its digits is 320, while the sum is 22.

Adding to 21121422151 its reverse (15122412112), we get a palindrome (36243834263).

The spelling of 21121422151 in words is "twenty-one billion, one hundred twenty-one million, four hundred twenty-two thousand, one hundred fifty-one".