78564357787538 has 12 divisors (see below), whose sum is σ = 137086787568222. Its totient is φ = 33670439051760.

The previous prime is 78564357787537. The next prime is 78564357787583. The reversal of 78564357787538 is 83578775346587.

It can be written as a sum of positive squares in only one way, i.e., 51349219910569 + 27215137876969 = 7165837^2 + 5216813^2 .

It is not an unprimeable number, because it can be changed into a prime (78564357787537) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 400838560043 + ... + 400838560238.

Almost surely, 2^{78564357787538} is an apocalyptic number.

78564357787538 is a deficient number, since it is larger than the sum of its proper divisors (58522429780684).

78564357787538 is a wasteful number, since it uses less digits than its factorization.

78564357787538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 801677120297 (or 801677120290 counting only the distinct ones).

The product of its digits is 33191424000, while the sum is 83.

The spelling of 78564357787538 in words is "seventy-eight trillion, five hundred sixty-four billion, three hundred fifty-seven million, seven hundred eighty-seven thousand, five hundred thirty-eight".