21787119751 has 2 divisors, whose sum is σ = 21787119752. Its totient is φ = 21787119750.

The previous prime is 21787119719. The next prime is 21787119773. The reversal of 21787119751 is 15791178712.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21787119751 - 2⁵ = 21787119719 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21787119695 and 21787119704.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21787119251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10893559875 + 10893559876.

It is an arithmetic number, because the mean of its divisors is an integer number (10893559876).

Almost surely, 2^21787119751 is an apocalyptic number.

21787119751 is a deficient number, since it is larger than the sum of its proper divisors (1).

21787119751 is an equidigital number, since it uses as much as digits as its factorization.

21787119751 is an evil number, because the sum of its binary digits is even.

The product of its digits is 246960, while the sum is 49.

The spelling of 21787119751 in words is "twenty-one billion, seven hundred eighty-seven million, one hundred nineteen thousand, seven hundred fifty-one".