81550384 has 20 divisors (see below), whose sum is σ = 158333616. Its totient is φ = 40690112.

The previous prime is 81550379. The next prime is 81550393. The reversal of 81550384 is 48305518.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2982 + ... + 13114.

Almost surely, 2^81550384 is an apocalyptic number.

It is an amenable number.

81550384 is a deficient number, since it is larger than the sum of its proper divisors (76783232).

81550384 is a wasteful number, since it uses less digits than its factorization.

81550384 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10644 (or 10638 counting only the distinct ones).

The product of its (nonzero) digits is 19200, while the sum is 34.

The square root of 81550384 is about 9030.5251231587. The cubic root of 81550384 is about 433.6526487996.

The spelling of 81550384 in words is "eighty-one million, five hundred fifty thousand, three hundred eighty-four".