121664425 has 24 divisors (see below), whose sum is σ = 159911640. Its totient is φ = 91660800.

The previous prime is 121664423. The next prime is 121664437. The reversal of 121664425 is 524466121.

It is a happy number.

It can be written as a sum of positive squares in 12 ways, for example, as 68359824 + 53304601 = 8268^2 + 7301^2 .

It is not a de Polignac number, because 121664425 - 2¹ = 121664423 is a prime.

It is not an unprimeable number, because it can be changed into a prime (121664423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 27679 + ... + 31771.

It is an arithmetic number, because the mean of its divisors is an integer number (6662985).

Almost surely, 2^121664425 is an apocalyptic number.

It is an amenable number.

121664425 is a deficient number, since it is larger than the sum of its proper divisors (38247215).

121664425 is a wasteful number, since it uses less digits than its factorization.

121664425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4173 (or 4168 counting only the distinct ones).

The product of its digits is 11520, while the sum is 31.

The square root of 121664425 is about 11030.1597903204. The cubic root of 121664425 is about 495.5124102405.

It can be divided in two parts, 1216644 and 25, that multiplied together give a triangular number (30416100 = T₇₇₉₉).

The spelling of 121664425 in words is "one hundred twenty-one million, six hundred sixty-four thousand, four hundred twenty-five".