81479121 has 4 divisors (see below), whose sum is σ = 108638832. Its totient is φ = 54319412.

The previous prime is 81479119. The next prime is 81479149. The reversal of 81479121 is 12197418.

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.

It is a cyclic number.

It is not a de Polignac number, because 81479121 - 2¹ = 81479119 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81479171) 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, 13579851 + ... + 13579856.

It is an arithmetic number, because the mean of its divisors is an integer number (27159708).

Almost surely, 2^81479121 is an apocalyptic number.

It is an amenable number.

81479121 is a deficient number, since it is larger than the sum of its proper divisors (27159711).

81479121 is a wasteful number, since it uses less digits than its factorization.

81479121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27159710.

The product of its digits is 4032, while the sum is 33.

The square root of 81479121 is about 9026.5785877042. The cubic root of 81479121 is about 433.5262958497.

The spelling of 81479121 in words is "eighty-one million, four hundred seventy-nine thousand, one hundred twenty-one".