77969553421369 has 3 divisors (see below), whose sum is σ = 77969562251407. Its totient is φ = 77969544591332.

The previous prime is 77969553421363. The next prime is 77969553421373. The reversal of 77969553421369 is 96312435596977.

The square root of 77969553421369 is 8830037.

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., 31350536714025 + 46619016707344 = 5599155^2 + 6827812^2 .

It is not a de Polignac number, because 77969553421369 - 2²³ = 77969545032761 is a prime.

It is a super-2 number, since 2×77969553421369² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 77969553421295 and 77969553421304.

It is not an unprimeable number, because it can be changed into a prime (77969553421363) 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, 4415019 + ... + 13245055.

Almost surely, 2^{77969553421369} is an apocalyptic number.

77969553421369 is the 8830037-th square number.

77969553421369 is the 4415019-th centered octagonal number.

It is an amenable number.

77969553421369 is a deficient number, since it is larger than the sum of its proper divisors (8830038).

77969553421369 is an frugal number, since it uses more digits than its factorization.

77969553421369 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17660074 (or 8830037 counting only the distinct ones).

The product of its digits is 2314720800, while the sum is 76.

The spelling of 77969553421369 in words is "seventy-seven trillion, nine hundred sixty-nine billion, five hundred fifty-three million, four hundred twenty-one thousand, three hundred sixty-nine".