771742923121 has 3 divisors (see below), whose sum is σ = 771743801611. Its totient is φ = 771742044632.

The previous prime is 771742923109. The next prime is 771742923139. The reversal of 771742923121 is 121329247177.

The square root of 771742923121 is 878489.

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: 121329247177 = 184879 ⋅656263.

It can be written as a sum of positive squares in only one way, i.e., 182533163121 + 589209760000 = 427239^2 + 767600^2 .

It is not a de Polignac number, because 771742923121 - 2¹⁷ = 771742792049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (771742927121) 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, 439245 + ... + 1317733.

Almost surely, 2^771742923121 is an apocalyptic number.

771742923121 is the 878489-th square number.

771742923121 is the 439245-th centered octagonal number.

It is an amenable number.

771742923121 is a deficient number, since it is larger than the sum of its proper divisors (878490).

771742923121 is an frugal number, since it uses more digits than its factorization.

771742923121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1756978 (or 878489 counting only the distinct ones).

The product of its digits is 296352, while the sum is 46.

The spelling of 771742923121 in words is "seven hundred seventy-one billion, seven hundred forty-two million, nine hundred twenty-three thousand, one hundred twenty-one".