81120431 has 12 divisors (see below), whose sum is σ = 95286672. Its totient is φ = 68852448.

The previous prime is 81120407. The next prime is 81120433. The reversal of 81120431 is 13402118.

It is not a de Polignac number, because 81120431 - 2¹⁴ = 81104047 is a prime.

It is a super-2 number, since 2×81120431² = 13161048651251522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81120433) 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, 2990 + ... + 13083.

It is an arithmetic number, because the mean of its divisors is an integer number (7940556).

Almost surely, 2^81120431 is an apocalyptic number.

81120431 is a deficient number, since it is larger than the sum of its proper divisors (14166241).

81120431 is a wasteful number, since it uses less digits than its factorization.

81120431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16190 (or 16183 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 20.

The square root of 81120431 is about 9006.6881260539. The cubic root of 81120431 is about 432.8891989285.

Adding to 81120431 its reverse (13402118), we get a palindrome (94522549).

The spelling of 81120431 in words is "eighty-one million, one hundred twenty thousand, four hundred thirty-one".