747778778861 has 4 divisors (see below), whose sum is σ = 747783233052. Its totient is φ = 747774324672.

The previous prime is 747778778819. The next prime is 747778778893. The reversal of 747778778861 is 168877877747.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 677715865225 + 70062913636 = 823235^2 + 264694^2 .

It is a cyclic number.

It is not a de Polignac number, because 747778778861 - 2¹⁴ = 747778762477 is a prime.

It is a super-3 number, since 3×747778778861³ (a number of 37 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (747778774861) 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, 1964990 + ... + 2314463.

It is an arithmetic number, because the mean of its divisors is an integer number (186945808263).

Almost surely, 2^747778778861 is an apocalyptic number.

It is an amenable number.

747778778861 is a deficient number, since it is larger than the sum of its proper divisors (4454191).

747778778861 is a wasteful number, since it uses less digits than its factorization.

747778778861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4454190.

The product of its digits is 1445670912, while the sum is 77.

The spelling of 747778778861 in words is "seven hundred forty-seven billion, seven hundred seventy-eight million, seven hundred seventy-eight thousand, eight hundred sixty-one".