81219874 has 8 divisors (see below), whose sum is σ = 121949100. Its totient is φ = 40570176.

The previous prime is 81219871. The next prime is 81219881. The reversal of 81219874 is 47891218.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 68310225 + 12909649 = 8265^2 + 3593^2 .

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 (81219871) 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, 17259 + ... + 21454.

Almost surely, 2^81219874 is an apocalyptic number.

81219874 is a deficient number, since it is larger than the sum of its proper divisors (40729226).

81219874 is a wasteful number, since it uses less digits than its factorization.

81219874 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39764.

The product of its digits is 32256, while the sum is 40.

The square root of 81219874 is about 9012.2069439178. The cubic root of 81219874 is about 433.0660151416.

The spelling of 81219874 in words is "eighty-one million, two hundred nineteen thousand, eight hundred seventy-four".