712438971721 has 3 divisors (see below), whose sum is σ = 712439815783. Its totient is φ = 712438127660.

The previous prime is 712438971701. The next prime is 712438971793. The reversal of 712438971721 is 127179834217.

The square root of 712438971721 is 844061.

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.

It can be written as a sum of positive squares in only one way, i.e., 163328331321 + 549110640400 = 404139^2 + 741020^2 .

It is not a de Polignac number, because 712438971721 - 2⁷ = 712438971593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (712438971701) 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, 422031 + ... + 1266091.

Almost surely, 2^712438971721 is an apocalyptic number.

712438971721 is the 844061-st square number.

712438971721 is the 422031-st centered octagonal number.

It is an amenable number.

712438971721 is a deficient number, since it is larger than the sum of its proper divisors (844062).

712438971721 is an frugal number, since it uses more digits than its factorization.

712438971721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1688122 (or 844061 counting only the distinct ones).

The product of its digits is 1185408, while the sum is 52.

The spelling of 712438971721 in words is "seven hundred twelve billion, four hundred thirty-eight million, nine hundred seventy-one thousand, seven hundred twenty-one".