997957643 has 2 divisors, whose sum is σ = 997957644. Its totient is φ = 997957642.

The previous prime is 997957601. The next prime is 997957651. The reversal of 997957643 is 346759799.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 997957643 - 2¹² = 997953547 is a prime.

It is not a weakly prime, because it can be changed into another prime (997956643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 498978821 + 498978822.

It is an arithmetic number, because the mean of its divisors is an integer number (498978822).

Almost surely, 2^997957643 is an apocalyptic number.

997957643 is a deficient number, since it is larger than the sum of its proper divisors (1).

997957643 is an equidigital number, since it uses as much as digits as its factorization.

997957643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12859560, while the sum is 59.

The square root of 997957643 is about 31590.4675970458. The cubic root of 997957643 is about 999.3187503376.

The spelling of 997957643 in words is "nine hundred ninety-seven million, nine hundred fifty-seven thousand, six hundred forty-three".