81431342 has 4 divisors (see below), whose sum is σ = 122147016. Its totient is φ = 40715670.

The previous prime is 81431341. The next prime is 81431369. The reversal of 81431342 is 24313418.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 24313418 = 2 ⋅12156709.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81431341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20357834 + ... + 20357837.

It is an arithmetic number, because the mean of its divisors is an integer number (30536754).

Almost surely, 2^81431342 is an apocalyptic number.

81431342 is a deficient number, since it is larger than the sum of its proper divisors (40715674).

81431342 is a wasteful number, since it uses less digits than its factorization.

81431342 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40715673.

The product of its digits is 2304, while the sum is 26.

The square root of 81431342 is about 9023.9316265140. The cubic root of 81431342 is about 433.4415399731.

The spelling of 81431342 in words is "eighty-one million, four hundred thirty-one thousand, three hundred forty-two".