1991367 has 24 divisors (see below), whose sum is σ = 3340064. Its totient is φ = 1119744.

The previous prime is 1991359. The next prime is 1991387. The reversal of 1991367 is 7631991.

It is not a de Polignac number, because 1991367 - 2³ = 1991359 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1991357) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4383 + ... + 4815.

2^1991367 is an apocalyptic number.

1991367 is a deficient number, since it is larger than the sum of its proper divisors (1348697).

1991367 is a wasteful number, since it uses less digits than its factorization.

1991367 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 519 (or 516 counting only the distinct ones).

The product of its digits is 10206, while the sum is 36.

The square root of 1991367 is about 1411.1580350903. The cubic root of 1991367 is about 125.8105618877.

The spelling of 1991367 in words is "one million, nine hundred ninety-one thousand, three hundred sixty-seven".