121541553 has 24 divisors (see below), whose sum is σ = 208074048. Its totient is φ = 69451344.

The previous prime is 121541549. The next prime is 121541573. The reversal of 121541553 is 355145121.

It is not a de Polignac number, because 121541553 - 2² = 121541549 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (121541543) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 34026 + ... + 37427.

It is an arithmetic number, because the mean of its divisors is an integer number (8669752).

Almost surely, 2^121541553 is an apocalyptic number.

It is an amenable number.

121541553 is a deficient number, since it is larger than the sum of its proper divisors (86532495).

121541553 is an frugal number, since it uses more digits than its factorization.

121541553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71475 (or 71463 counting only the distinct ones).

The product of its digits is 3000, while the sum is 27.

The square root of 121541553 is about 11024.5885637515. The cubic root of 121541553 is about 495.3455438546.

Adding to 121541553 its reverse (355145121), we get a palindrome (476686674).

The spelling of 121541553 in words is "one hundred twenty-one million, five hundred forty-one thousand, five hundred fifty-three".