21661224633203 has 2 divisors, whose sum is σ = 21661224633204. Its totient is φ = 21661224633202.

The previous prime is 21661224633127. The next prime is 21661224633241. The reversal of 21661224633203 is 30233642216612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21661224633203 - 2¹⁴ = 21661224616819 is a prime.

It is a super-2 number, since 2×21661224633203² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21661224633703) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10830612316601 + 10830612316602.

It is an arithmetic number, because the mean of its divisors is an integer number (10830612316602).

Almost surely, 2^{21661224633203} is an apocalyptic number.

21661224633203 is a deficient number, since it is larger than the sum of its proper divisors (1).

21661224633203 is an equidigital number, since it uses as much as digits as its factorization.

21661224633203 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 373248, while the sum is 41.

Adding to 21661224633203 its reverse (30233642216612), we get a palindrome (51894866849815).

The spelling of 21661224633203 in words is "twenty-one trillion, six hundred sixty-one billion, two hundred twenty-four million, six hundred thirty-three thousand, two hundred three".