1931291 has 2 divisors, whose sum is σ = 1931292. Its totient is φ = 1931290.

The previous prime is 1931273. The next prime is 1931297. The reversal of 1931291 is 1921391.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1931291 - 2⁶ = 1931227 is a prime.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 1931291.

It is not a weakly prime, because it can be changed into another prime (1931297) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 965645 + 965646.

It is an arithmetic number, because the mean of its divisors is an integer number (965646).

2^1931291 is an apocalyptic number.

1931291 is a deficient number, since it is larger than the sum of its proper divisors (1).

1931291 is an equidigital number, since it uses as much as digits as its factorization.

1931291 is an evil number, because the sum of its binary digits is even.

The product of its digits is 486, while the sum is 26.

The square root of 1931291 is about 1389.7089623371. The cubic root of 1931291 is about 124.5324614418.

It can be divided in two parts, 1931 and 291, that added together give a palindrome (2222).

The spelling of 1931291 in words is "one million, nine hundred thirty-one thousand, two hundred ninety-one".