11891431 has 2 divisors, whose sum is σ = 11891432. Its totient is φ = 11891430.

The previous prime is 11891413. The next prime is 11891461. The reversal of 11891431 is 13419811.

Together with previous prime (11891413) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 11891431 - 2⁷ = 11891303 is a prime.

It is a super-2 number, since 2×11891431² = 282812262455522, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 11891431.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11891461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5945715 + 5945716.

It is an arithmetic number, because the mean of its divisors is an integer number (5945716).

Almost surely, 2^11891431 is an apocalyptic number.

11891431 is a deficient number, since it is larger than the sum of its proper divisors (1).

11891431 is an equidigital number, since it uses as much as digits as its factorization.

11891431 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 864, while the sum is 28.

The square root of 11891431 is about 3448.3954239617. The cubic root of 11891431 is about 228.2503086123.

The spelling of 11891431 in words is "eleven million, eight hundred ninety-one thousand, four hundred thirty-one".