121635613 has 24 divisors (see below), whose sum is σ = 139187160. Its totient is φ = 106128000.

The previous prime is 121635611. The next prime is 121635617. The reversal of 121635613 is 316536121.

It can be written as a sum of positive squares in 4 ways, for example, as 44582329 + 77053284 = 6677^2 + 8778^2 .

It is not a de Polignac number, because 121635613 - 2¹ = 121635611 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121635611) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 452043 + ... + 452311.

It is an arithmetic number, because the mean of its divisors is an integer number (5799465).

Almost surely, 2^121635613 is an apocalyptic number.

It is an amenable number.

121635613 is a deficient number, since it is larger than the sum of its proper divisors (17551547).

121635613 is a wasteful number, since it uses less digits than its factorization.

121635613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 429 (or 418 counting only the distinct ones).

The product of its digits is 3240, while the sum is 28.

The square root of 121635613 is about 11028.8536575657. The cubic root of 121635613 is about 495.4732921754.

The spelling of 121635613 in words is "one hundred twenty-one million, six hundred thirty-five thousand, six hundred thirteen".