69661 has 2 divisors, whose sum is σ = 69662. Its totient is φ = 69660.

The previous prime is 69653. The next prime is 69677. The reversal of 69661 is 16696.

69661 = T₂₁₄ + T₂₁₅ + T₂₁₆.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 42436 + 27225 = 206^2 + 165^2 .

It is a cyclic number.

It is not a de Polignac number, because 69661 - 2³ = 69653 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (69691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34830 + 34831.

It is an arithmetic number, because the mean of its divisors is an integer number (34831).

2⁶⁹⁶⁶¹ is an apocalyptic number.

69661 is the 216-th centered triangular number.

It is an amenable number.

69661 is a deficient number, since it is larger than the sum of its proper divisors (1).

69661 is an equidigital number, since it uses as much as digits as its factorization.

69661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1944, while the sum is 28.

The square root of 69661 is about 263.9337037970. The cubic root of 69661 is about 41.1462159910.

It can be divided in two parts, 696 and 61, that added together give a palindrome (757).

The spelling of 69661 in words is "sixty-nine thousand, six hundred sixty-one".