81953850 has 48 divisors (see below), whose sum is σ = 221726880. Its totient is φ = 19867200.

The previous prime is 81953849. The next prime is 81953857. The reversal of 81953850 is 5835918.

It is a junction number, because it is equal to n+sod(n) for n = 81953799 and 81953808.

It is not an unprimeable number, because it can be changed into a prime (81953857) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 23185 + ... + 26484.

It is an arithmetic number, because the mean of its divisors is an integer number (4619310).

Almost surely, 2^81953850 is an apocalyptic number.

81953850 is an abundant number, since it is smaller than the sum of its proper divisors (139773030).

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

81953850 is a wasteful number, since it uses less digits than its factorization.

81953850 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49695 (or 49690 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 39.

The square root of 81953850 is about 9052.8365720364. The cubic root of 81953850 is about 434.3666301029.

The spelling of 81953850 in words is "eighty-one million, nine hundred fifty-three thousand, eight hundred fifty".