81245713405 has 8 divisors (see below), whose sum is σ = 97499962584. Its totient is φ = 64993166400.

The previous prime is 81245713397. The next prime is 81245713427. The reversal of 81245713405 is 50431754218.

It can be written as a sum of positive squares in 4 ways, for example, as 6295152964 + 74950560441 = 79342^2 + 273771^2 .

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

It is not a de Polignac number, because 81245713405 - 2³ = 81245713397 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 318066 + ... + 513475.

It is an arithmetic number, because the mean of its divisors is an integer number (12187495323).

Almost surely, 2^81245713405 is an apocalyptic number.

It is an amenable number.

81245713405 is a deficient number, since it is larger than the sum of its proper divisors (16254249179).

81245713405 is a wasteful number, since it uses less digits than its factorization.

81245713405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 851087.

The product of its (nonzero) digits is 134400, while the sum is 40.

The spelling of 81245713405 in words is "eighty-one billion, two hundred forty-five million, seven hundred thirteen thousand, four hundred five".