21111010109953 has 2 divisors, whose sum is σ = 21111010109954. Its totient is φ = 21111010109952.

The previous prime is 21111010109881. The next prime is 21111010110019. The reversal of 21111010109953 is 35990101011112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12605574487489 + 8505435622464 = 3550433^2 + 2916408^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21111010109953 is a prime.

It is not a weakly prime, because it can be changed into another prime (21111010109053) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555505054976 + 10555505054977.

It is an arithmetic number, because the mean of its divisors is an integer number (10555505054977).

Almost surely, 2^{21111010109953} is an apocalyptic number.

It is an amenable number.

21111010109953 is a deficient number, since it is larger than the sum of its proper divisors (1).

21111010109953 is an equidigital number, since it uses as much as digits as its factorization.

21111010109953 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2430, while the sum is 34.

The spelling of 21111010109953 in words is "twenty-one trillion, one hundred eleven billion, ten million, one hundred nine thousand, nine hundred fifty-three".