81633942 has 48 divisors (see below), whose sum is σ = 191711520. Its totient is φ = 24955776.

The previous prime is 81633901. The next prime is 81633953. The reversal of 81633942 is 24933618.

It is a junction number, because it is equal to n+sod(n) for n = 81633897 and 81633906.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 38034 + ... + 40122.

It is an arithmetic number, because the mean of its divisors is an integer number (3993990).

Almost surely, 2^81633942 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81633942, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (95855760).

81633942 is an abundant number, since it is smaller than the sum of its proper divisors (110077578).

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

81633942 is a wasteful number, since it uses less digits than its factorization.

81633942 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2277 (or 2274 counting only the distinct ones).

The product of its digits is 31104, while the sum is 36.

The square root of 81633942 is about 9035.1503584611. The cubic root of 81633942 is about 433.8007076951.

The spelling of 81633942 in words is "eighty-one million, six hundred thirty-three thousand, nine hundred forty-two".