997777771 has 2 divisors, whose sum is σ = 997777772. Its totient is φ = 997777770.

The previous prime is 997777757. The next prime is 997777783. The reversal of 997777771 is 177777799.

It is a strong prime.

It is an emirp because it is prime and its reverse (177777799) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 997777771 - 2⁷ = 997777643 is a prime.

It is a nialpdrome in base 10.

It is not a weakly prime, because it can be changed into another prime (997772771) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 498888885 + 498888886.

It is an arithmetic number, because the mean of its divisors is an integer number (498888886).

Almost surely, 2^997777771 is an apocalyptic number.

997777771 is a deficient number, since it is larger than the sum of its proper divisors (1).

997777771 is an equidigital number, since it uses as much as digits as its factorization.

997777771 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9529569, while the sum is 61.

The square root of 997777771 is about 31587.6205340003. The cubic root of 997777771 is about 999.2587076214.

The spelling of 997777771 in words is "nine hundred ninety-seven million, seven hundred seventy-seven thousand, seven hundred seventy-one".