81119431 has 2 divisors, whose sum is σ = 81119432. Its totient is φ = 81119430.

The previous prime is 81119377. The next prime is 81119449. The reversal of 81119431 is 13491118.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81119431 - 2¹¹ = 81117383 is a prime.

It is a super-2 number, since 2×81119431² = 13160724171527522, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81119431.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81111431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40559715 + 40559716.

It is an arithmetic number, because the mean of its divisors is an integer number (40559716).

Almost surely, 2^81119431 is an apocalyptic number.

81119431 is a deficient number, since it is larger than the sum of its proper divisors (1).

81119431 is an equidigital number, since it uses as much as digits as its factorization.

81119431 is an evil number, because the sum of its binary digits is even.

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

The square root of 81119431 is about 9006.6326115813. The cubic root of 81119431 is about 432.8874201288.

The spelling of 81119431 in words is "eighty-one million, one hundred nineteen thousand, four hundred thirty-one".