77778478477 has 16 divisors (see below), whose sum is σ = 89803763712. Its totient is φ = 65982449520.

The previous prime is 77778478423. The next prime is 77778478573. The reversal of 77778478477 is 77487487777.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77778478477 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77778478777) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1275948 + ... + 1335514.

It is an arithmetic number, because the mean of its divisors is an integer number (5612735232).

Almost surely, 2^77778478477 is an apocalyptic number.

It is an amenable number.

77778478477 is a deficient number, since it is larger than the sum of its proper divisors (12025285235).

77778478477 is a wasteful number, since it uses less digits than its factorization.

77778478477 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61488.

The product of its digits is 843308032, while the sum is 73.

The spelling of 77778478477 in words is "seventy-seven billion, seven hundred seventy-eight million, four hundred seventy-eight thousand, four hundred seventy-seven".