121664 has 14 divisors (see below), whose sum is σ = 241554. Its totient is φ = 60800.

The previous prime is 121661. The next prime is 121687. The reversal of 121664 is 466121.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 78400 + 43264 = 280^2 + 208^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 887 + ... + 1014.

2¹²¹⁶⁶⁴ is an apocalyptic number.

It is an amenable number.

121664 is a deficient number, since it is larger than the sum of its proper divisors (119890).

121664 is an equidigital number, since it uses as much as digits as its factorization.

121664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1913 (or 1903 counting only the distinct ones).

The product of its digits is 288, while the sum is 20.

The square root of 121664 is about 348.8036697055. The cubic root of 121664 is about 49.5511833263.

Adding to 121664 its reverse (466121), we get a palindrome (587785).

The spelling of 121664 in words is "one hundred twenty-one thousand, six hundred sixty-four".