55115421 has 4 divisors (see below), whose sum is σ = 73487232. Its totient is φ = 36743612.

The previous prime is 55115419. The next prime is 55115441. The reversal of 55115421 is 12451155.

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 55115421 - 2¹ = 55115419 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 55115391 and 55115400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55115441) 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, 9185901 + ... + 9185906.

It is an arithmetic number, because the mean of its divisors is an integer number (18371808).

Almost surely, 2^55115421 is an apocalyptic number.

It is an amenable number.

55115421 is a deficient number, since it is larger than the sum of its proper divisors (18371811).

55115421 is a wasteful number, since it uses less digits than its factorization.

55115421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18371810.

The product of its digits is 1000, while the sum is 24.

The square root of 55115421 is about 7423.9760910175. The cubic root of 55115421 is about 380.5610847944.

Adding to 55115421 its reverse (12451155), we get a palindrome (67566576).

The spelling of 55115421 in words is "fifty-five million, one hundred fifteen thousand, four hundred twenty-one".