21038657433961 has 2 divisors, whose sum is σ = 21038657433962. Its totient is φ = 21038657433960.

The previous prime is 21038657433929. The next prime is 21038657434021. The reversal of 21038657433961 is 16933475683012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13754158995600 + 7284498438361 = 3708660^2 + 2698981^2 .

It is a cyclic number.

It is not a de Polignac number, because 21038657433961 - 2⁵ = 21038657433929 is a prime.

It is a super-2 number, since 2×21038657433961² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21038657433896 and 21038657433905.

It is not a weakly prime, because it can be changed into another prime (21038657403961) 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, 10519328716980 + 10519328716981.

It is an arithmetic number, because the mean of its divisors is an integer number (10519328716981).

It is a 1-persistent number, because it is pandigital, but 2⋅21038657433961 = 42077314867922 is not.

Almost surely, 2^{21038657433961} is an apocalyptic number.

It is an amenable number.

21038657433961 is a deficient number, since it is larger than the sum of its proper divisors (1).

21038657433961 is an equidigital number, since it uses as much as digits as its factorization.

21038657433961 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 19595520, while the sum is 58.

The spelling of 21038657433961 in words is "twenty-one trillion, thirty-eight billion, six hundred fifty-seven million, four hundred thirty-three thousand, nine hundred sixty-one".