81431534 has 8 divisors (see below), whose sum is σ = 122260008. Its totient is φ = 40678200.

The previous prime is 81431527. The next prime is 81431563. The reversal of 81431534 is 43513418.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 81431497 and 81431506.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15992 + ... + 20459.

It is an arithmetic number, because the mean of its divisors is an integer number (15282501).

Almost surely, 2^81431534 is an apocalyptic number.

81431534 is a deficient number, since it is larger than the sum of its proper divisors (40828474).

81431534 is a wasteful number, since it uses less digits than its factorization.

81431534 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37570.

The product of its digits is 5760, while the sum is 29.

The square root of 81431534 is about 9023.9422648862. The cubic root of 81431534 is about 433.4418806311.

The spelling of 81431534 in words is "eighty-one million, four hundred thirty-one thousand, five hundred thirty-four".