81407471 has 4 divisors (see below), whose sum is σ = 83300712. Its totient is φ = 79514232.

The previous prime is 81407449. The next prime is 81407477. The reversal of 81407471 is 17470418.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81407471 - 2¹⁸ = 81145327 is a prime.

It is a super-3 number, since 3×81407471³ (a number of 25 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81407477) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 946556 + ... + 946641.

It is an arithmetic number, because the mean of its divisors is an integer number (20825178).

Almost surely, 2^81407471 is an apocalyptic number.

81407471 is a deficient number, since it is larger than the sum of its proper divisors (1893241).

81407471 is a wasteful number, since it uses less digits than its factorization.

81407471 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1893240.

The product of its (nonzero) digits is 6272, while the sum is 32.

The square root of 81407471 is about 9022.6088799194. The cubic root of 81407471 is about 433.3991824323.

Adding to 81407471 its reverse (17470418), we get a palindrome (98877889).

The spelling of 81407471 in words is "eighty-one million, four hundred seven thousand, four hundred seventy-one".