81409263 has 16 divisors (see below), whose sum is σ = 118379520. Its totient is φ = 49461984.

The previous prime is 81409261. The next prime is 81409291. The reversal of 81409263 is 36290418.

It is not a de Polignac number, because 81409263 - 2¹ = 81409261 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81409261) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10131 + ... + 16292.

It is an arithmetic number, because the mean of its divisors is an integer number (7398720).

Almost surely, 2^81409263 is an apocalyptic number.

81409263 is a deficient number, since it is larger than the sum of its proper divisors (36970257).

81409263 is a wasteful number, since it uses less digits than its factorization.

81409263 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26518.

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 81409263 is about 9022.7081854618. The cubic root of 81409263 is about 433.4023625075.

The spelling of 81409263 in words is "eighty-one million, four hundred nine thousand, two hundred sixty-three".