81261235 has 8 divisors (see below), whose sum is σ = 106378416. Its totient is φ = 59099040.

The previous prime is 81261209. The next prime is 81261239. The reversal of 81261235 is 53216218.

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

It is not a de Polignac number, because 81261235 - 2⁵ = 81261203 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81261239) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 738684 + ... + 738793.

It is an arithmetic number, because the mean of its divisors is an integer number (13297302).

Almost surely, 2^81261235 is an apocalyptic number.

81261235 is a deficient number, since it is larger than the sum of its proper divisors (25117181).

81261235 is a wasteful number, since it uses less digits than its factorization.

81261235 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1477493.

The product of its digits is 2880, while the sum is 28.

The square root of 81261235 is about 9014.5013727882. The cubic root of 81261235 is about 433.1395152300.

The spelling of 81261235 in words is "eighty-one million, two hundred sixty-one thousand, two hundred thirty-five".