81231049 has 8 divisors (see below), whose sum is σ = 86088960. Its totient is φ = 76382016.

The previous prime is 81231047. The next prime is 81231071. The reversal of 81231049 is 94013218.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 81231049 - 2¹ = 81231047 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81231043) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30672 + ... + 33214.

It is an arithmetic number, because the mean of its divisors is an integer number (10761120).

Almost surely, 2^81231049 is an apocalyptic number.

It is an amenable number.

81231049 is a deficient number, since it is larger than the sum of its proper divisors (4857911).

81231049 is a wasteful number, since it uses less digits than its factorization.

81231049 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4439.

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 81231049 is about 9012.8269150140. The cubic root of 81231049 is about 433.0858760063.

The spelling of 81231049 in words is "eighty-one million, two hundred thirty-one thousand, forty-nine".