81436738 has 8 divisors (see below), whose sum is σ = 123414732. Its totient is φ = 40298496.

The previous prime is 81436723. The next prime is 81436753. The reversal of 81436738 is 83763418.

It is an interprime number because it is at equal distance from previous prime (81436723) and next prime (81436753).

It can be written as a sum of positive squares in 2 ways, for example, as 76160529 + 5276209 = 8727^2 + 2297^2 .

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

It is a plaindrome in base 12.

It is a self number, because there is not a number n which added to its sum of digits gives 81436738.

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, 209695 + ... + 210082.

Almost surely, 2^81436738 is an apocalyptic number.

81436738 is a deficient number, since it is larger than the sum of its proper divisors (41977994).

81436738 is a wasteful number, since it uses less digits than its factorization.

81436738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 419876.

The product of its digits is 96768, while the sum is 40.

The square root of 81436738 is about 9024.2306043230. The cubic root of 81436738 is about 433.4511136779.

The spelling of 81436738 in words is "eighty-one million, four hundred thirty-six thousand, seven hundred thirty-eight".