81006547974 has 16 divisors (see below), whose sum is σ = 176741559360. Its totient is φ = 24547438760.

The previous prime is 81006547967. The next prime is 81006548039. The reversal of 81006547974 is 47974560018.

It is a Smith number, since the sum of its digits (51) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 613685904 + ... + 613686035.

It is an arithmetic number, because the mean of its divisors is an integer number (11046347460).

Almost surely, 2^81006547974 is an apocalyptic number.

81006547974 is an abundant number, since it is smaller than the sum of its proper divisors (95735011386).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81006547974 is a wasteful number, since it uses less digits than its factorization.

81006547974 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1227371955.

The product of its (nonzero) digits is 1693440, while the sum is 51.

The spelling of 81006547974 in words is "eighty-one billion, six million, five hundred forty-seven thousand, nine hundred seventy-four".