81212842 has 8 divisors (see below), whose sum is σ = 128985156. Its totient is φ = 38217792.

The previous prime is 81212819. The next prime is 81212863. The reversal of 81212842 is 24821218.

It can be written as a sum of positive squares in 2 ways, for example, as 66765241 + 14447601 = 8171^2 + 3801^2 .

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

It is a self number, because there is not a number n which added to its sum of digits gives 81212842.

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, 1194273 + ... + 1194340.

Almost surely, 2^81212842 is an apocalyptic number.

81212842 is a deficient number, since it is larger than the sum of its proper divisors (47772314).

81212842 is a wasteful number, since it uses less digits than its factorization.

81212842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2388632.

The product of its digits is 2048, while the sum is 28.

The square root of 81212842 is about 9011.8167979603. The cubic root of 81212842 is about 433.0535165254.

The spelling of 81212842 in words is "eighty-one million, two hundred twelve thousand, eight hundred forty-two".