77720045537 has 2 divisors, whose sum is σ = 77720045538. Its totient is φ = 77720045536.

The previous prime is 77720045521. The next prime is 77720045563. The reversal of 77720045537 is 73554002777.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 55543176976 + 22176868561 = 235676^2 + 148919^2 .

It is a cyclic number.

It is not a de Polignac number, because 77720045537 - 2⁴ = 77720045521 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 77720045491 and 77720045500.

It is not a weakly prime, because it can be changed into another prime (77720045237) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38860022768 + 38860022769.

It is an arithmetic number, because the mean of its divisors is an integer number (38860022769).

Almost surely, 2^77720045537 is an apocalyptic number.

It is an amenable number.

77720045537 is a deficient number, since it is larger than the sum of its proper divisors (1).

77720045537 is an equidigital number, since it uses as much as digits as its factorization.

77720045537 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1440600, while the sum is 47.

The spelling of 77720045537 in words is "seventy-seven billion, seven hundred twenty million, forty-five thousand, five hundred thirty-seven".