121891556 has 6 divisors (see below), whose sum is σ = 213310230. Its totient is φ = 60945776.

The previous prime is 121891537. The next prime is 121891571. The reversal of 121891556 is 655198121.

It can be written as a sum of positive squares in only one way, i.e., 120253156 + 1638400 = 10966^2 + 1280^2 .

It is a super-2 number, since 2×121891556² = 29715102848202272, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15236441 + ... + 15236448.

It is an arithmetic number, because the mean of its divisors is an integer number (35551705).

Almost surely, 2^121891556 is an apocalyptic number.

It is an amenable number.

121891556 is a deficient number, since it is larger than the sum of its proper divisors (91418674).

121891556 is a wasteful number, since it uses less digits than its factorization.

121891556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30472893 (or 30472891 counting only the distinct ones).

The product of its digits is 21600, while the sum is 38.

The square root of 121891556 is about 11040.4508965893. The cubic root of 121891556 is about 495.8205700706.

The spelling of 121891556 in words is "one hundred twenty-one million, eight hundred ninety-one thousand, five hundred fifty-six".