55550421 has 16 divisors (see below), whose sum is σ = 82470720. Its totient is φ = 36955440.

The previous prime is 55550371. The next prime is 55550423. The reversal of 55550421 is 12405555.

It is not a de Polignac number, because 55550421 - 2⁹ = 55549909 is a prime.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55550423) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12706 + ... + 16508.

It is an arithmetic number, because the mean of its divisors is an integer number (5154420).

Almost surely, 2^55550421 is an apocalyptic number.

It is an amenable number.

55550421 is a deficient number, since it is larger than the sum of its proper divisors (26920299).

55550421 is a wasteful number, since it uses less digits than its factorization.

55550421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4353 (or 4347 counting only the distinct ones).

The product of its (nonzero) digits is 5000, while the sum is 27.

The square root of 55550421 is about 7453.2154805829. The cubic root of 55550421 is about 381.5596586245.

Adding to 55550421 its reverse (12405555), we get a palindrome (67955976).

The spelling of 55550421 in words is "fifty-five million, five hundred fifty thousand, four hundred twenty-one".