55421445520221 has 16 divisors (see below), whose sum is σ = 80650734282048. Its totient is φ = 33573037104000.

The previous prime is 55421445520213. The next prime is 55421445520223. The reversal of 55421445520221 is 12202554412455.

It is not a de Polignac number, because 55421445520221 - 2³ = 55421445520213 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55421445520223) 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, 392872330 + ... + 393013371.

It is an arithmetic number, because the mean of its divisors is an integer number (5040670892628).

Almost surely, 2^{55421445520221} is an apocalyptic number.

It is an amenable number.

55421445520221 is a deficient number, since it is larger than the sum of its proper divisors (25229288761827).

55421445520221 is a wasteful number, since it uses less digits than its factorization.

55421445520221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 785887852.

The product of its (nonzero) digits is 640000, while the sum is 42.

Adding to 55421445520221 its reverse (12202554412455), we get a palindrome (67623999932676).

The spelling of 55421445520221 in words is "fifty-five trillion, four hundred twenty-one billion, four hundred forty-five million, five hundred twenty thousand, two hundred twenty-one".