55551061021 has 2 divisors, whose sum is σ = 55551061022. Its totient is φ = 55551061020.

The previous prime is 55551060997. The next prime is 55551061057. The reversal of 55551061021 is 12016015555.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 44684040996 + 10867020025 = 211386^2 + 104245^2 .

It is a cyclic number.

It is not a de Polignac number, because 55551061021 - 2¹¹ = 55551058973 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55551064021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27775530510 + 27775530511.

It is an arithmetic number, because the mean of its divisors is an integer number (27775530511).

Almost surely, 2^55551061021 is an apocalyptic number.

It is an amenable number.

55551061021 is a deficient number, since it is larger than the sum of its proper divisors (1).

55551061021 is an equidigital number, since it uses as much as digits as its factorization.

55551061021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7500, while the sum is 31.

Adding to 55551061021 its reverse (12016015555), we get a palindrome (67567076576).

The spelling of 55551061021 in words is "fifty-five billion, five hundred fifty-one million, sixty-one thousand, twenty-one".