21111573751 has 2 divisors, whose sum is σ = 21111573752. Its totient is φ = 21111573750.

The previous prime is 21111573673. The next prime is 21111573757. The reversal of 21111573751 is 15737511112.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21111573751 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21111573757) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555786875 + 10555786876.

It is an arithmetic number, because the mean of its divisors is an integer number (10555786876).

Almost surely, 2^21111573751 is an apocalyptic number.

21111573751 is a deficient number, since it is larger than the sum of its proper divisors (1).

21111573751 is an equidigital number, since it uses as much as digits as its factorization.

21111573751 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7350, while the sum is 34.

The spelling of 21111573751 in words is "twenty-one billion, one hundred eleven million, five hundred seventy-three thousand, seven hundred fifty-one".