81798356 has 24 divisors (see below), whose sum is σ = 151865280. Its totient is φ = 38417792.

The previous prime is 81798349. The next prime is 81798389. The reversal of 81798356 is 65389718.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 81798356.

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, 49715 + ... + 51333.

It is an arithmetic number, because the mean of its divisors is an integer number (6327720).

Almost surely, 2^81798356 is an apocalyptic number.

It is an amenable number.

81798356 is a deficient number, since it is larger than the sum of its proper divisors (70066924).

81798356 is a wasteful number, since it uses less digits than its factorization.

81798356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2383 (or 2381 counting only the distinct ones).

The product of its digits is 362880, while the sum is 47.

The square root of 81798356 is about 9044.2443576011. The cubic root of 81798356 is about 434.0917430125.

The spelling of 81798356 in words is "eighty-one million, seven hundred ninety-eight thousand, three hundred fifty-six".