81197238 has 24 divisors (see below), whose sum is σ = 163770984. Its totient is φ = 26837760.

The previous prime is 81197197. The next prime is 81197273. The reversal of 81197238 is 83279118.

It is a junction number, because it is equal to n+sod(n) for n = 81197196 and 81197205.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 336798 + ... + 337038.

It is an arithmetic number, because the mean of its divisors is an integer number (6823791).

Almost surely, 2^81197238 is an apocalyptic number.

81197238 is an abundant number, since it is smaller than the sum of its proper divisors (82573746).

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

81197238 is a wasteful number, since it uses less digits than its factorization.

81197238 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 720 (or 479 counting only the distinct ones).

The product of its digits is 24192, while the sum is 39.

The square root of 81197238 is about 9010.9510041948. The cubic root of 81197238 is about 433.0257795332.

The spelling of 81197238 in words is "eighty-one million, one hundred ninety-seven thousand, two hundred thirty-eight".