121643615 has 4 divisors (see below), whose sum is σ = 145972344. Its totient is φ = 97314888.

The previous prime is 121643611. The next prime is 121643629. The reversal of 121643615 is 516346121.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 121643615 - 2² = 121643611 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 (121643611) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12164357 + ... + 12164366.

It is an arithmetic number, because the mean of its divisors is an integer number (36493086).

Almost surely, 2^121643615 is an apocalyptic number.

121643615 is a deficient number, since it is larger than the sum of its proper divisors (24328729).

121643615 is an equidigital number, since it uses as much as digits as its factorization.

121643615 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24328728.

The product of its digits is 4320, while the sum is 29.

The square root of 121643615 is about 11029.2164272898. The cubic root of 121643615 is about 495.4841571139.

Adding to 121643615 its reverse (516346121), we get a palindrome (637989736).

The spelling of 121643615 in words is "one hundred twenty-one million, six hundred forty-three thousand, six hundred fifteen".