81451699 has 8 divisors (see below), whose sum is σ = 94477568. Its totient is φ = 68773320.

The previous prime is 81451681. The next prime is 81451723. The reversal of 81451699 is 99615418.

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

It is not a de Polignac number, because 81451699 - 2⁹ = 81451187 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81451099) 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, 86367 + ... + 87304.

It is an arithmetic number, because the mean of its divisors is an integer number (11809696).

Almost surely, 2^81451699 is an apocalyptic number.

81451699 is a deficient number, since it is larger than the sum of its proper divisors (13025869).

81451699 is a wasteful number, since it uses less digits than its factorization.

81451699 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173745.

The product of its digits is 77760, while the sum is 43.

The square root of 81451699 is about 9025.0595011889. The cubic root of 81451699 is about 433.4776556097.

The spelling of 81451699 in words is "eighty-one million, four hundred fifty-one thousand, six hundred ninety-nine".