121561221 has 8 divisors (see below), whose sum is σ = 170612320. Its totient is φ = 76775472.

The previous prime is 121561211. The next prime is 121561241. The reversal of 121561221 is 122165121.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 121561221 - 2⁶ = 121561157 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 (121561211) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1066270 + ... + 1066383.

It is an arithmetic number, because the mean of its divisors is an integer number (21326540).

Almost surely, 2^121561221 is an apocalyptic number.

It is an amenable number.

121561221 is a deficient number, since it is larger than the sum of its proper divisors (49051099).

121561221 is a wasteful number, since it uses less digits than its factorization.

121561221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2132675.

The product of its digits is 240, while the sum is 21.

The square root of 121561221 is about 11025.4805337455. The cubic root of 121561221 is about 495.3722615503.

The spelling of 121561221 in words is "one hundred twenty-one million, five hundred sixty-one thousand, two hundred twenty-one".