81625911 has 16 divisors (see below), whose sum is σ = 111682560. Its totient is φ = 53000640.

The previous prime is 81625903. The next prime is 81625927. The reversal of 81625911 is 11952618.

It is not a de Polignac number, because 81625911 - 2³ = 81625903 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81625961) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 61131 + ... + 62451.

It is an arithmetic number, because the mean of its divisors is an integer number (6980160).

Almost surely, 2^81625911 is an apocalyptic number.

81625911 is a deficient number, since it is larger than the sum of its proper divisors (30056649).

81625911 is a wasteful number, since it uses less digits than its factorization.

81625911 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1846.

The product of its digits is 4320, while the sum is 33.

The square root of 81625911 is about 9034.7059166306. The cubic root of 81625911 is about 433.7864817181.

The spelling of 81625911 in words is "eighty-one million, six hundred twenty-five thousand, nine hundred eleven".