121005553 has 4 divisors (see below), whose sum is σ = 126266688. Its totient is φ = 115744420.

The previous prime is 121005539. The next prime is 121005581. The reversal of 121005553 is 355500121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 121005553 - 2¹³ = 120997361 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (121005593) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2630533 + ... + 2630578.

It is an arithmetic number, because the mean of its divisors is an integer number (31566672).

Almost surely, 2^121005553 is an apocalyptic number.

It is an amenable number.

121005553 is a deficient number, since it is larger than the sum of its proper divisors (5261135).

121005553 is an equidigital number, since it uses as much as digits as its factorization.

121005553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5261134.

The product of its (nonzero) digits is 750, while the sum is 22.

The square root of 121005553 is about 11000.2524061951. The cubic root of 121005553 is about 494.6163104966.

Adding to 121005553 its reverse (355500121), we get a palindrome (476505674).

The spelling of 121005553 in words is "one hundred twenty-one million, five thousand, five hundred fifty-three".