997447639 has 2 divisors, whose sum is σ = 997447640. Its totient is φ = 997447638.

The previous prime is 997447609. The next prime is 997447657. The reversal of 997447639 is 936744799.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-997447639 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (997447609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 498723819 + 498723820.

It is an arithmetic number, because the mean of its divisors is an integer number (498723820).

Almost surely, 2^997447639 is an apocalyptic number.

997447639 is a deficient number, since it is larger than the sum of its proper divisors (1).

997447639 is an equidigital number, since it uses as much as digits as its factorization.

997447639 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10287648, while the sum is 58.

The square root of 997447639 is about 31582.3944469066. The cubic root of 997447639 is about 999.1484881333.

The spelling of 997447639 in words is "nine hundred ninety-seven million, four hundred forty-seven thousand, six hundred thirty-nine".