71721262777 has 4 divisors (see below), whose sum is σ = 71721798400. Its totient is φ = 71720727156.

The previous prime is 71721262771. The next prime is 71721262819. The reversal of 71721262777 is 77726212717.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 77726212717 = 2729 ⋅28481573.

It is a cyclic number.

It is not a de Polignac number, because 71721262777 - 2¹¹ = 71721260729 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 71721262777.

It is not an unprimeable number, because it can be changed into a prime (71721262771) 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, 132088 + ... + 401110.

It is an arithmetic number, because the mean of its divisors is an integer number (17930449600).

Almost surely, 2^71721262777 is an apocalyptic number.

It is an amenable number.

71721262777 is a deficient number, since it is larger than the sum of its proper divisors (535623).

71721262777 is a wasteful number, since it uses less digits than its factorization.

71721262777 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 535622.

The product of its digits is 806736, while the sum is 49.

The spelling of 71721262777 in words is "seventy-one billion, seven hundred twenty-one million, two hundred sixty-two thousand, seven hundred seventy-seven".