1997027091 has 18 divisors (see below), whose sum is σ = 3044410980. Its totient is φ = 1261278216.

The previous prime is 1997027083. The next prime is 1997027143. The reversal of 1997027091 is 1907207991.

It is not a de Polignac number, because 1997027091 - 2³ = 1997027083 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1997027051) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 304081 + ... + 310578.

Almost surely, 2^1997027091 is an apocalyptic number.

1997027091 is a deficient number, since it is larger than the sum of its proper divisors (1047383889).

1997027091 is a wasteful number, since it uses less digits than its factorization.

1997027091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 614703 (or 614681 counting only the distinct ones).

The product of its (nonzero) digits is 71442, while the sum is 45.

The square root of 1997027091 is about 44688.1090559894. The cubic root of 1997027091 is about 1259.2964685506.

The spelling of 1997027091 in words is "one billion, nine hundred ninety-seven million, twenty-seven thousand, ninety-one".