70661 has 4 divisors (see below), whose sum is σ = 74400. Its totient is φ = 66924.

The previous prime is 70657. The next prime is 70663. The reversal of 70661 is 16607.

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 not a de Polignac number, because 70661 - 2² = 70657 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (70663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1841 + ... + 1878.

It is an arithmetic number, because the mean of its divisors is an integer number (18600).

2⁷⁰⁶⁶¹ is an apocalyptic number.

It is an amenable number.

70661 is a deficient number, since it is larger than the sum of its proper divisors (3739).

70661 is a wasteful number, since it uses less digits than its factorization.

70661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3738.

The product of its (nonzero) digits is 252, while the sum is 20.

The square root of 70661 is about 265.8213685918. The cubic root of 70661 is about 41.3421691713.

It can be divided in two parts, 706 and 61, that added together give a palindrome (767).

The spelling of 70661 in words is "seventy thousand, six hundred sixty-one".