81218950 has 24 divisors (see below), whose sum is σ = 154755720. Its totient is φ = 31694400.

The previous prime is 81218927. The next prime is 81218953. The reversal of 81218950 is 5981218.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81218953) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 17760 + ... + 21859.

It is an arithmetic number, because the mean of its divisors is an integer number (6448155).

Almost surely, 2^81218950 is an apocalyptic number.

81218950 is a deficient number, since it is larger than the sum of its proper divisors (73536770).

81218950 is a wasteful number, since it uses less digits than its factorization.

81218950 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39672 (or 39667 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 34.

The square root of 81218950 is about 9012.1556799691. The cubic root of 81218950 is about 433.0643728732.

It can be divided in two parts, 8121 and 8950, that added together give a palindrome (17071).

The spelling of 81218950 in words is "eighty-one million, two hundred eighteen thousand, nine hundred fifty".