81531146 has 8 divisors (see below), whose sum is σ = 124019424. Its totient is φ = 40191340.

The previous prime is 81531143. The next prime is 81531169. The reversal of 81531146 is 64113518.

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

It is not an unprimeable number, because it can be changed into a prime (81531143) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 286940 + ... + 287223.

It is an arithmetic number, because the mean of its divisors is an integer number (15502428).

Almost surely, 2^81531146 is an apocalyptic number.

81531146 is a deficient number, since it is larger than the sum of its proper divisors (42488278).

81531146 is a wasteful number, since it uses less digits than its factorization.

81531146 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 574236.

The product of its digits is 2880, while the sum is 29.

The square root of 81531146 is about 9029.4598952540. The cubic root of 81531146 is about 433.6185460958.

The spelling of 81531146 in words is "eighty-one million, five hundred thirty-one thousand, one hundred forty-six".