121555536 has 40 divisors (see below), whose sum is σ = 320705664. Its totient is φ = 39655680.

The previous prime is 121555519. The next prime is 121555537. The reversal of 121555536 is 635555121.

It is a junction number, because it is equal to n+sod(n) for n = 121555497 and 121555506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121555537) 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, 24685 + ... + 29196.

Almost surely, 2^121555536 is an apocalyptic number.

121555536 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

121555536 is an abundant number, since it is smaller than the sum of its proper divisors (199150128).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

121555536 is a wasteful number, since it uses less digits than its factorization.

121555536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53939 (or 53933 counting only the distinct ones).

The product of its digits is 22500, while the sum is 33.

The square root of 121555536 is about 11025.2227188388. Note that the first 3 decimals coincide. The cubic root of 121555536 is about 495.3645391446.

The spelling of 121555536 in words is "one hundred twenty-one million, five hundred fifty-five thousand, five hundred thirty-six".