55500000100021 has 2 divisors, whose sum is σ = 55500000100022. Its totient is φ = 55500000100020.

The previous prime is 55500000099983. The next prime is 55500000100033. The reversal of 55500000100021 is 12000100000555.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 33087965901796 + 22412034198225 = 5752214^2 + 4734135^2 .

It is a cyclic number.

It is not a de Polignac number, because 55500000100021 - 2³⁵ = 55465640361653 is a prime.

It is a super-2 number, since 2×55500000100021² (a number of 28 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55500000100091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27750000050010 + 27750000050011.

It is an arithmetic number, because the mean of its divisors is an integer number (27750000050011).

Almost surely, 2^{55500000100021} is an apocalyptic number.

It is an amenable number.

55500000100021 is a deficient number, since it is larger than the sum of its proper divisors (1).

55500000100021 is an equidigital number, since it uses as much as digits as its factorization.

55500000100021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 250, while the sum is 19.

Adding to 55500000100021 its reverse (12000100000555), we get a palindrome (67500100100576).

The spelling of 55500000100021 in words is "fifty-five trillion, five hundred billion, one hundred thousand, twenty-one".