55531210421 has 2 divisors, whose sum is σ = 55531210422. Its totient is φ = 55531210420.

The previous prime is 55531210391. The next prime is 55531210459. The reversal of 55531210421 is 12401213555.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 54632050225 + 899160196 = 233735^2 + 29986^2 .

It is a cyclic number.

It is not a de Polignac number, because 55531210421 - 2²² = 55527016117 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55531110421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27765605210 + 27765605211.

It is an arithmetic number, because the mean of its divisors is an integer number (27765605211).

Almost surely, 2^55531210421 is an apocalyptic number.

It is an amenable number.

55531210421 is a deficient number, since it is larger than the sum of its proper divisors (1).

55531210421 is an equidigital number, since it uses as much as digits as its factorization.

55531210421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6000, while the sum is 29.

Adding to 55531210421 its reverse (12401213555), we get a palindrome (67932423976).

The spelling of 55531210421 in words is "fifty-five billion, five hundred thirty-one million, two hundred ten thousand, four hundred twenty-one".