21175378051 has 2 divisors, whose sum is σ = 21175378052. Its totient is φ = 21175378050.

The previous prime is 21175378043. The next prime is 21175378069. The reversal of 21175378051 is 15087357112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21175378051 - 2³ = 21175378043 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21175377995 and 21175378013.

It is not a weakly prime, because it can be changed into another prime (21175376051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10587689025 + 10587689026.

It is an arithmetic number, because the mean of its divisors is an integer number (10587689026).

Almost surely, 2^21175378051 is an apocalyptic number.

21175378051 is a deficient number, since it is larger than the sum of its proper divisors (1).

21175378051 is an equidigital number, since it uses as much as digits as its factorization.

21175378051 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 58800, while the sum is 40.

The spelling of 21175378051 in words is "twenty-one billion, one hundred seventy-five million, three hundred seventy-eight thousand, fifty-one".