21603223353557 has 2 divisors, whose sum is σ = 21603223353558. Its totient is φ = 21603223353556.

The previous prime is 21603223353529. The next prime is 21603223353587. The reversal of 21603223353557 is 75535332230612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17806703600401 + 3796519753156 = 4219799^2 + 1948466^2 .

It is a cyclic number.

It is not a de Polignac number, because 21603223353557 - 2¹⁴ = 21603223337173 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21603223353587) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10801611676778 + 10801611676779.

It is an arithmetic number, because the mean of its divisors is an integer number (10801611676779).

Almost surely, 2^{21603223353557} is an apocalyptic number.

It is an amenable number.

21603223353557 is a deficient number, since it is larger than the sum of its proper divisors (1).

21603223353557 is an equidigital number, since it uses as much as digits as its factorization.

21603223353557 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3402000, while the sum is 47.

The spelling of 21603223353557 in words is "twenty-one trillion, six hundred three billion, two hundred twenty-three million, three hundred fifty-three thousand, five hundred fifty-seven".