81556422 has 16 divisors (see below), whose sum is σ = 165411072. Its totient is φ = 26802440.

The previous prime is 81556411. The next prime is 81556441. The reversal of 81556422 is 22465518.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 95298 + ... + 96149.

It is an arithmetic number, because the mean of its divisors is an integer number (10338192).

Almost surely, 2^81556422 is an apocalyptic number.

81556422 is an abundant number, since it is smaller than the sum of its proper divisors (83854650).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81556422 is a wasteful number, since it uses less digits than its factorization.

81556422 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 191523.

The product of its digits is 19200, while the sum is 33.

The square root of 81556422 is about 9030.8594275407. The cubic root of 81556422 is about 433.6633510998.

The spelling of 81556422 in words is "eighty-one million, five hundred fifty-six thousand, four hundred twenty-two".