997071691 has 16 divisors (see below), whose sum is σ = 1244263680. Its totient is φ = 776213280.

The previous prime is 997071679. The next prime is 997071701. The reversal of 997071691 is 196170799.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 997071691 - 2¹⁷ = 996940619 is a prime.

It is not an unprimeable number, because it can be changed into a prime (997077691) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 85945 + ... + 96853.

It is an arithmetic number, because the mean of its divisors is an integer number (77766480).

Almost surely, 2^997071691 is an apocalyptic number.

997071691 is a deficient number, since it is larger than the sum of its proper divisors (247191989).

997071691 is a wasteful number, since it uses less digits than its factorization.

997071691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12114.

The product of its (nonzero) digits is 214326, while the sum is 49.

The square root of 997071691 is about 31576.4420256621. The cubic root of 997071691 is about 999.0229426699.

The spelling of 997071691 in words is "nine hundred ninety-seven million, seventy-one thousand, six hundred ninety-one".