81561167 has 8 divisors (see below), whose sum is σ = 86002560. Its totient is φ = 77134680.

The previous prime is 81561163. The next prime is 81561229. The reversal of 81561167 is 76116518.

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

It is not a de Polignac number, because 81561167 - 2² = 81561163 is a prime.

It is a super-3 number, since 3×81561167³ (a number of 25 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81561163) 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, 8588 + ... + 15390.

It is an arithmetic number, because the mean of its divisors is an integer number (10750320).

Almost surely, 2^81561167 is an apocalyptic number.

81561167 is a deficient number, since it is larger than the sum of its proper divisors (4441393).

81561167 is a wasteful number, since it uses less digits than its factorization.

81561167 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7453.

The product of its digits is 10080, while the sum is 35.

The square root of 81561167 is about 9031.1221340429. The cubic root of 81561167 is about 433.6717611986.

The spelling of 81561167 in words is "eighty-one million, five hundred sixty-one thousand, one hundred sixty-seven".