55590421 has 2 divisors, whose sum is σ = 55590422. Its totient is φ = 55590420.

The previous prime is 55590397. The next prime is 55590433. The reversal of 55590421 is 12409555.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 43375396 + 12215025 = 6586^2 + 3495^2 .

It is a cyclic number.

It is not a de Polignac number, because 55590421 - 2⁵ = 55590389 is a prime.

It is equal to p_3315289 and since 55590421 and 3315289 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55590461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27795210 + 27795211.

It is an arithmetic number, because the mean of its divisors is an integer number (27795211).

Almost surely, 2^55590421 is an apocalyptic number.

It is an amenable number.

55590421 is a deficient number, since it is larger than the sum of its proper divisors (1).

55590421 is an equidigital number, since it uses as much as digits as its factorization.

55590421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9000, while the sum is 31.

The square root of 55590421 is about 7455.8984032778. The cubic root of 55590421 is about 381.6512194338.

Adding to 55590421 its reverse (12409555), we get a palindrome (67999976).

The spelling of 55590421 in words is "fifty-five million, five hundred ninety thousand, four hundred twenty-one".