121620913 has 6 divisors (see below), whose sum is σ = 124265906. Its totient is φ = 119031072.

The previous prime is 121620901. The next prime is 121620929. The reversal of 121620913 is 319026121.

It can be written as a sum of positive squares in only one way, i.e., 84860944 + 36759969 = 9212^2 + 6063^2 .

It is a de Polignac number, because none of the positive numbers 2^k-121620913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121620973) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 25320 + ... + 29737.

Almost surely, 2^121620913 is an apocalyptic number.

It is an amenable number.

121620913 is a deficient number, since it is larger than the sum of its proper divisors (2644993).

121620913 is an frugal number, since it uses more digits than its factorization.

121620913 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55151 (or 55104 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 25.

The square root of 121620913 is about 11028.1872037067. The cubic root of 121620913 is about 495.4533315990.

The spelling of 121620913 in words is "one hundred twenty-one million, six hundred twenty thousand, nine hundred thirteen".