21113217151 has 24 divisors (see below), whose sum is σ = 23865425280. Its totient is φ = 18648115200.

The previous prime is 21113217131. The next prime is 21113217157. The reversal of 21113217151 is 15171231112.

It is a happy number.

It is not a de Polignac number, because 21113217151 - 2⁹ = 21113216639 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 (21113217157) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 443631 + ... + 488911.

It is an arithmetic number, because the mean of its divisors is an integer number (994392720).

Almost surely, 2^21113217151 is an apocalyptic number.

21113217151 is a deficient number, since it is larger than the sum of its proper divisors (2752208129).

21113217151 is a wasteful number, since it uses less digits than its factorization.

21113217151 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45427 (or 45414 counting only the distinct ones).

The product of its digits is 420, while the sum is 25.

Adding to 21113217151 its reverse (15171231112), we get a palindrome (36284448263).

The spelling of 21113217151 in words is "twenty-one billion, one hundred thirteen million, two hundred seventeen thousand, one hundred fifty-one".