77491019477 has 2 divisors, whose sum is σ = 77491019478. Its totient is φ = 77491019476.

The previous prime is 77491019443. The next prime is 77491019479.

It is a happy number.

77491019477 is nontrivially palindromic in base 10.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 48838348036 + 28652671441 = 220994^2 + 169271^2 .

It is a palprime.

It is a cyclic number.

It is not a de Polignac number, because 77491019477 - 2²² = 77486825173 is a prime.

Together with 77491019479, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77491019479) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38745509738 + 38745509739.

It is an arithmetic number, because the mean of its divisors is an integer number (38745509739).

Almost surely, 2^77491019477 is an apocalyptic number.

It is an amenable number.

77491019477 is a deficient number, since it is larger than the sum of its proper divisors (1).

77491019477 is an equidigital number, since it uses as much as digits as its factorization.

77491019477 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3111696, while the sum is 56.

The spelling of 77491019477 in words is "seventy-seven billion, four hundred ninety-one million, nineteen thousand, four hundred seventy-seven".