81825291 has 12 divisors (see below), whose sum is σ = 119957032. Its totient is φ = 53735616.

The previous prime is 81825281. The next prime is 81825307. The reversal of 81825291 is 19252818.

It is not a de Polignac number, because 81825291 - 2¹⁵ = 81792523 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81825281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 67246 + ... + 68451.

Almost surely, 2^81825291 is an apocalyptic number.

81825291 is a deficient number, since it is larger than the sum of its proper divisors (38131741).

81825291 is a wasteful number, since it uses less digits than its factorization.

81825291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135770 (or 135767 counting only the distinct ones).

The product of its digits is 11520, while the sum is 36.

The square root of 81825291 is about 9045.7333036078. The cubic root of 81825291 is about 434.1393844670.

The spelling of 81825291 in words is "eighty-one million, eight hundred twenty-five thousand, two hundred ninety-one".