55400121 has 24 divisors (see below), whose sum is σ = 94610880. Its totient is φ = 30564576.

The previous prime is 55400117. The next prime is 55400129. The reversal of 55400121 is 12100455.

55400121 is a `hidden beast` number, since 5 + 540 + 0 + 121 = 666.

It is not a de Polignac number, because 55400121 - 2² = 55400117 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 55400094 and 55400103.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55400129) 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, 13335 + ... + 16988.

It is an arithmetic number, because the mean of its divisors is an integer number (3942120).

Almost surely, 2^55400121 is an apocalyptic number.

It is an amenable number.

55400121 is a deficient number, since it is larger than the sum of its proper divisors (39210759).

55400121 is a wasteful number, since it uses less digits than its factorization.

55400121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30365 (or 30362 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 18.

The square root of 55400121 is about 7443.1257546813. The cubic root of 55400121 is about 381.2152254944.

Adding to 55400121 its reverse (12100455), we get a palindrome (67500576).

The spelling of 55400121 in words is "fifty-five million, four hundred thousand, one hundred twenty-one".