81261478459 has 8 divisors (see below), whose sum is σ = 93722282720. Its totient is φ = 69013679616.

The previous prime is 81261478427. The next prime is 81261478489. The reversal of 81261478459 is 95487416218.

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

It is not a de Polignac number, because 81261478459 - 2⁵ = 81261478427 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81261478489) 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, 53250534 + ... + 53252059.

It is an arithmetic number, because the mean of its divisors is an integer number (11715285340).

Almost surely, 2^81261478459 is an apocalyptic number.

81261478459 is a deficient number, since it is larger than the sum of its proper divisors (12460804261).

81261478459 is a wasteful number, since it uses less digits than its factorization.

81261478459 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106502709.

The product of its digits is 3870720, while the sum is 55.

The spelling of 81261478459 in words is "eighty-one billion, two hundred sixty-one million, four hundred seventy-eight thousand, four hundred fifty-nine".