81833820 has 24 divisors (see below), whose sum is σ = 229134864. Its totient is φ = 21822336.

The previous prime is 81833813. The next prime is 81833863. The reversal of 81833820 is 2833818.

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, 681889 + ... + 682008.

It is an arithmetic number, because the mean of its divisors is an integer number (9547286).

Almost surely, 2^81833820 is an apocalyptic number.

It is an amenable number.

81833820 is an abundant number, since it is smaller than the sum of its proper divisors (147301044).

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

81833820 is a wasteful number, since it uses less digits than its factorization.

81833820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1363909 (or 1363907 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 33.

The square root of 81833820 is about 9046.2047290563. The cubic root of 81833820 is about 434.1544680111.

The spelling of 81833820 in words is "eighty-one million, eight hundred thirty-three thousand, eight hundred twenty".