81147701 has 4 divisors (see below), whose sum is σ = 81177600. Its totient is φ = 81117804.

The previous prime is 81147679. The next prime is 81147707. The reversal of 81147701 is 10774118.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 10774118 = 2 ⋅5387059.

It is a cyclic number.

It is not a de Polignac number, because 81147701 - 2⁶ = 81147637 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81147707) 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, 10421 + ... + 16458.

It is an arithmetic number, because the mean of its divisors is an integer number (20294400).

Almost surely, 2^81147701 is an apocalyptic number.

It is an amenable number.

81147701 is a deficient number, since it is larger than the sum of its proper divisors (29899).

81147701 is a wasteful number, since it uses less digits than its factorization.

81147701 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29898.

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

The square root of 81147701 is about 9008.2018738481. The cubic root of 81147701 is about 432.9377011605.

The spelling of 81147701 in words is "eighty-one million, one hundred forty-seven thousand, seven hundred one".