1997091 has 12 divisors (see below), whose sum is σ = 2934360. Its totient is φ = 1308480.

The previous prime is 1997089. The next prime is 1997101. The reversal of 1997091 is 1907991.

It is not a de Polignac number, because 1997091 - 2¹ = 1997089 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1997081) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1350 + ... + 2411.

It is an arithmetic number, because the mean of its divisors is an integer number (244530).

2^1997091 is an apocalyptic number.

1997091 is a deficient number, since it is larger than the sum of its proper divisors (937269).

1997091 is a wasteful number, since it uses less digits than its factorization.

1997091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3826 (or 3823 counting only the distinct ones).

The product of its (nonzero) digits is 5103, while the sum is 36.

The square root of 1997091 is about 1413.1847013041. The cubic root of 1997091 is about 125.9309901772.

The spelling of 1997091 in words is "one million, nine hundred ninety-seven thousand, ninety-one".