81072567 has 6 divisors (see below), whose sum is σ = 117104832. Its totient is φ = 54048372.

The previous prime is 81072547. The next prime is 81072569. The reversal of 81072567 is 76527018.

It is not a de Polignac number, because 81072567 - 2¹¹ = 81070519 is a prime.

It is a super-2 number, since 2×81072567² = 13145522239938978, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81072569) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4504023 + ... + 4504040.

It is an arithmetic number, because the mean of its divisors is an integer number (19517472).

Almost surely, 2^81072567 is an apocalyptic number.

81072567 is a deficient number, since it is larger than the sum of its proper divisors (36032265).

81072567 is a wasteful number, since it uses less digits than its factorization.

81072567 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9008069 (or 9008066 counting only the distinct ones).

The product of its (nonzero) digits is 23520, while the sum is 36.

The square root of 81072567 is about 9004.0305974602. The cubic root of 81072567 is about 432.8040420621.

The spelling of 81072567 in words is "eighty-one million, seventy-two thousand, five hundred sixty-seven".