73661 has 8 divisors (see below), whose sum is σ = 89280. Its totient is φ = 59328.

The previous prime is 73651. The next prime is 73673. The reversal of 73661 is 16637.

73661 = 29² + 30² + ... + 62².

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 73661 - 2⁶ = 73597 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (73651) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 191 + ... + 428.

It is an arithmetic number, because the mean of its divisors is an integer number (11160).

2⁷³⁶⁶¹ is an apocalyptic number.

It is an amenable number.

73661 is a deficient number, since it is larger than the sum of its proper divisors (15619).

73661 is a wasteful number, since it uses less digits than its factorization.

73661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 643.

The product of its digits is 756, while the sum is 23.

The square root of 73661 is about 271.4056005318. The cubic root of 73661 is about 41.9191566585.

It can be divided in two parts, 736 and 61, that added together give a palindrome (797).

The spelling of 73661 in words is "seventy-three thousand, six hundred sixty-one".