121643621 has 4 divisors (see below), whose sum is σ = 132702144. Its totient is φ = 110585100.

The previous prime is 121643611. The next prime is 121643629. The reversal of 121643621 is 126346121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 121643621 - 2¹⁰ = 121642597 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121643629) 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, 5529245 + ... + 5529266.

It is an arithmetic number, because the mean of its divisors is an integer number (33175536).

Almost surely, 2^121643621 is an apocalyptic number.

121643621 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

121643621 is a deficient number, since it is larger than the sum of its proper divisors (11058523).

121643621 is a wasteful number, since it uses less digits than its factorization.

121643621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11058522.

The product of its digits is 1728, while the sum is 26.

The square root of 121643621 is about 11029.2166992947. The cubic root of 121643621 is about 495.4841652603.

Adding to 121643621 its reverse (126346121), we get a palindrome (247989742).

The spelling of 121643621 in words is "one hundred twenty-one million, six hundred forty-three thousand, six hundred twenty-one".