724551111022121 has 4 divisors (see below), whose sum is σ = 724551275530500. Its totient is φ = 724550946513744.

The previous prime is 724551111022111. The next prime is 724551111022147. The reversal of 724551111022121 is 121220111155427.

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

It can be written as a sum of positive squares in 2 ways, for example, as 578444059146496 + 146107051875625 = 24050864^2 + 12087475^2 .

It is a cyclic number.

It is not a de Polignac number, because 724551111022121 - 2¹⁸ = 724551110759977 is a prime.

It is a super-2 number, since 2×724551111022121² (a number of 31 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (724551111022111) 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, 75460646 + ... + 84518703.

It is an arithmetic number, because the mean of its divisors is an integer number (181137818882625).

Almost surely, 2^{724551111022121} is an apocalyptic number.

It is an amenable number.

724551111022121 is a deficient number, since it is larger than the sum of its proper divisors (164508379).

724551111022121 is a wasteful number, since it uses less digits than its factorization.

724551111022121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 164508378.

The product of its (nonzero) digits is 11200, while the sum is 35.

Adding to 724551111022121 its reverse (121220111155427), we get a palindrome (845771222177548).

The spelling of 724551111022121 in words is "seven hundred twenty-four trillion, five hundred fifty-one billion, one hundred eleven million, twenty-two thousand, one hundred twenty-one".