81147107 has 4 divisors (see below), whose sum is σ = 82290096. Its totient is φ = 80004120.

The previous prime is 81147097. The next prime is 81147109. The reversal of 81147107 is 70174118.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81147107 - 2⁴ = 81147091 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81147107.

It is not an unprimeable number, because it can be changed into a prime (81147109) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 571388 + ... + 571529.

It is an arithmetic number, because the mean of its divisors is an integer number (20572524).

Almost surely, 2^81147107 is an apocalyptic number.

81147107 is a deficient number, since it is larger than the sum of its proper divisors (1142989).

81147107 is a wasteful number, since it uses less digits than its factorization.

81147107 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1142988.

The product of its (nonzero) digits is 1568, while the sum is 29.

The square root of 81147107 is about 9008.1689038339. The cubic root of 81147107 is about 432.9366447920.

The spelling of 81147107 in words is "eighty-one million, one hundred forty-seven thousand, one hundred seven".