121531556 has 6 divisors (see below), whose sum is σ = 212680230. Its totient is φ = 60765776.

The previous prime is 121531549. The next prime is 121531559. The reversal of 121531556 is 655135121.

It can be written as a sum of positive squares in only one way, i.e., 83905600 + 37625956 = 9160^2 + 6134^2 .

It is a super-2 number, since 2×121531556² = 29539838207562272, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (121531559) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15191441 + ... + 15191448.

It is an arithmetic number, because the mean of its divisors is an integer number (35446705).

Almost surely, 2^121531556 is an apocalyptic number.

It is an amenable number.

121531556 is a deficient number, since it is larger than the sum of its proper divisors (91148674).

121531556 is a wasteful number, since it uses less digits than its factorization.

121531556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30382893 (or 30382891 counting only the distinct ones).

The product of its digits is 4500, while the sum is 29.

The square root of 121531556 is about 11024.1351588231. The cubic root of 121531556 is about 495.3319624770.

Adding to 121531556 its reverse (655135121), we get a palindrome (776666677).

The spelling of 121531556 in words is "one hundred twenty-one million, five hundred thirty-one thousand, five hundred fifty-six".