77561300906 has 4 divisors (see below), whose sum is σ = 116341951362. Its totient is φ = 38780650452.

The previous prime is 77561300881. The next prime is 77561300923. The reversal of 77561300906 is 60900316577.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 60900316577 = 116791 ⋅521447.

It can be written as a sum of positive squares in only one way, i.e., 75465034681 + 2096266225 = 274709^2 + 45785^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19390325225 + ... + 19390325228.

Almost surely, 2^77561300906 is an apocalyptic number.

77561300906 is a deficient number, since it is larger than the sum of its proper divisors (38780650456).

77561300906 is a wasteful number, since it uses less digits than its factorization.

77561300906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38780650455.

The product of its (nonzero) digits is 238140, while the sum is 44.

The spelling of 77561300906 in words is "seventy-seven billion, five hundred sixty-one million, three hundred thousand, nine hundred six".