81422473 has 6 divisors (see below), whose sum is σ = 89497562. Its totient is φ = 74020320.

The previous prime is 81422449. The next prime is 81422491. The reversal of 81422473 is 37422418.

It can be written as a sum of positive squares in only one way, i.e., 50808384 + 30614089 = 7128^2 + 5533^2 .

It is not a de Polignac number, because 81422473 - 2⁵ = 81422441 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81422423) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 336336 + ... + 336577.

Almost surely, 2^81422473 is an apocalyptic number.

It is an amenable number.

81422473 is a deficient number, since it is larger than the sum of its proper divisors (8075089).

81422473 is a wasteful number, since it uses less digits than its factorization.

81422473 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 672935 (or 672924 counting only the distinct ones).

The product of its digits is 10752, while the sum is 31.

The square root of 81422473 is about 9023.4401976186. The cubic root of 81422473 is about 433.4258034746.

The spelling of 81422473 in words is "eighty-one million, four hundred twenty-two thousand, four hundred seventy-three".