81087799 has 8 divisors (see below), whose sum is σ = 90336960. Its totient is φ = 72268896.

The previous prime is 81087779. The next prime is 81087817. The reversal of 81087799 is 99778018.

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 81087799 - 2⁵ = 81087767 is a prime.

It is a super-2 number, since 2×81087799² = 13150462293328802, which contains 22 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 (81087779) 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, 107167 + ... + 107920.

It is an arithmetic number, because the mean of its divisors is an integer number (11292120).

Almost surely, 2^81087799 is an apocalyptic number.

81087799 is a deficient number, since it is larger than the sum of its proper divisors (9249161).

81087799 is a wasteful number, since it uses less digits than its factorization.

81087799 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215129.

The product of its (nonzero) digits is 254016, while the sum is 49.

The square root of 81087799 is about 9004.8764011507. The cubic root of 81087799 is about 432.8311455925.

The spelling of 81087799 in words is "eighty-one million, eighty-seven thousand, seven hundred ninety-nine".