724645290121 has 3 divisors (see below), whose sum is σ = 724646141383. Its totient is φ = 724644438860.

The previous prime is 724645290113. The next prime is 724645290251. The reversal of 724645290121 is 121092546427.

The square root of 724645290121 is 851261.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 121092546427 = 69557 ⋅1740911.

It can be written as a sum of positive squares in only one way, i.e., 434361401721 + 290283888400 = 659061^2 + 538780^2 .

It is not a de Polignac number, because 724645290121 - 2³ = 724645290113 is a prime.

It is a super-2 number, since 2×724645290121² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (724645297121) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 425631 + ... + 1276891.

Almost surely, 2^724645290121 is an apocalyptic number.

724645290121 is the 851261-st square number.

724645290121 is the 425631-st centered octagonal number.

It is an amenable number.

724645290121 is a deficient number, since it is larger than the sum of its proper divisors (851262).

724645290121 is an frugal number, since it uses more digits than its factorization.

724645290121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1702522 (or 851261 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 43.

The spelling of 724645290121 in words is "seven hundred twenty-four billion, six hundred forty-five million, two hundred ninety thousand, one hundred twenty-one".