997777643 has 2 divisors, whose sum is σ = 997777644. Its totient is φ = 997777642.

The previous prime is 997777619. The next prime is 997777657. The reversal of 997777643 is 346777799.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 997777643 - 2⁸ = 997777387 is a prime.

It is a Chen prime.

It is a nialpdrome in base 10.

It is not a weakly prime, because it can be changed into another prime (997777603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 498888821 + 498888822.

It is an arithmetic number, because the mean of its divisors is an integer number (498888822).

Almost surely, 2^997777643 is an apocalyptic number.

997777643 is a deficient number, since it is larger than the sum of its proper divisors (1).

997777643 is an equidigital number, since it uses as much as digits as its factorization.

997777643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 14002632, while the sum is 59.

The square root of 997777643 is about 31587.6185078901. The cubic root of 997777643 is about 999.2586648914.

The spelling of 997777643 in words is "nine hundred ninety-seven million, seven hundred seventy-seven thousand, six hundred forty-three".