81973154 has 8 divisors (see below), whose sum is σ = 123743388. Its totient is φ = 40725360.

The previous prime is 81973147. The next prime is 81973159. The reversal of 81973154 is 45137918.

It can be written as a sum of positive squares in 2 ways, for example, as 77880625 + 4092529 = 8825^2 + 2023^2 .

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 (81973159) 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, 130217 + ... + 130844.

Almost surely, 2^81973154 is an apocalyptic number.

81973154 is a deficient number, since it is larger than the sum of its proper divisors (41770234).

81973154 is a wasteful number, since it uses less digits than its factorization.

81973154 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 261220.

The product of its digits is 30240, while the sum is 38.

The square root of 81973154 is about 9053.9026944186. The cubic root of 81973154 is about 434.4007320401.

The spelling of 81973154 in words is "eighty-one million, nine hundred seventy-three thousand, one hundred fifty-four".