77773236557 has 2 divisors, whose sum is σ = 77773236558. Its totient is φ = 77773236556.

The previous prime is 77773236533. The next prime is 77773236577. The reversal of 77773236557 is 75563237777.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 77065091236 + 708145321 = 277606^2 + 26611^2 .

It is an emirp because it is prime and its reverse (75563237777) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77773236557 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 77773236496 and 77773236505.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77773236577) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38886618278 + 38886618279.

It is an arithmetic number, because the mean of its divisors is an integer number (38886618279).

Almost surely, 2^77773236557 is an apocalyptic number.

It is an amenable number.

77773236557 is a deficient number, since it is larger than the sum of its proper divisors (1).

77773236557 is an equidigital number, since it uses as much as digits as its factorization.

77773236557 is an evil number, because the sum of its binary digits is even.

The product of its digits is 45378900, while the sum is 59.

The spelling of 77773236557 in words is "seventy-seven billion, seven hundred seventy-three million, two hundred thirty-six thousand, five hundred fifty-seven".