21185362739 has 2 divisors, whose sum is σ = 21185362740. Its totient is φ = 21185362738.

The previous prime is 21185362717. The next prime is 21185362817. The reversal of 21185362739 is 93726358112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21185362739 - 2⁸ = 21185362483 is a prime.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 21185362693 and 21185362702.

It is not a weakly prime, because it can be changed into another prime (21185361739) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10592681369 + 10592681370.

It is an arithmetic number, because the mean of its divisors is an integer number (10592681370).

Almost surely, 2^21185362739 is an apocalyptic number.

21185362739 is a deficient number, since it is larger than the sum of its proper divisors (1).

21185362739 is an equidigital number, since it uses as much as digits as its factorization.

21185362739 is an evil number, because the sum of its binary digits is even.

The product of its digits is 544320, while the sum is 47.

The spelling of 21185362739 in words is "twenty-one billion, one hundred eighty-five million, three hundred sixty-two thousand, seven hundred thirty-nine".