67661 has 4 divisors (see below), whose sum is σ = 73824. Its totient is φ = 61500.

The previous prime is 67651. The next prime is 67679. The reversal of 67661 is 16676.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-67661 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 67661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (67601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3065 + ... + 3086.

It is an arithmetic number, because the mean of its divisors is an integer number (18456).

2⁶⁷⁶⁶¹ is an apocalyptic number.

It is an amenable number.

67661 is a deficient number, since it is larger than the sum of its proper divisors (6163).

67661 is a wasteful number, since it uses less digits than its factorization.

67661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6162.

The product of its digits is 1512, while the sum is 26.

The square root of 67661 is about 260.1172812406. The cubic root of 67661 is about 40.7486104887.

It can be divided in two parts, 676 and 61, that added together give a palindrome (737).

The spelling of 67661 in words is "sixty-seven thousand, six hundred sixty-one".