73638981 has 48 divisors (see below), whose sum is σ = 120207360. Its totient is φ = 43130880.

The previous prime is 73638979. The next prime is 73638997. The reversal of 73638981 is 18983637.

It is a happy number.

73638981 is a `hidden beast` number, since 7 + 3 + 638 + 9 + 8 + 1 = 666.

It is not a de Polignac number, because 73638981 - 2¹ = 73638979 is a prime.

It is a super-2 number, since 2×73638981² = 10845399045436722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (73633981) 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 47 ways as a sum of consecutive naturals, for example, 286405 + ... + 286661.

It is an arithmetic number, because the mean of its divisors is an integer number (2504320).

Almost surely, 2^73638981 is an apocalyptic number.

It is an amenable number.

73638981 is a deficient number, since it is larger than the sum of its proper divisors (46568379).

73638981 is a wasteful number, since it uses less digits than its factorization.

73638981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 386 (or 383 counting only the distinct ones).

The product of its digits is 217728, while the sum is 45.

The square root of 73638981 is about 8581.3158081963. The cubic root of 73638981 is about 419.1497936935.

The spelling of 73638981 in words is "seventy-three million, six hundred thirty-eight thousand, nine hundred eighty-one".