21149094773 has 2 divisors, whose sum is σ = 21149094774. Its totient is φ = 21149094772.

The previous prime is 21149094761. The next prime is 21149094781. The reversal of 21149094773 is 37749094112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10912309444 + 10236785329 = 104462^2 + 101177^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21149094773 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21149090773) 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, 10574547386 + 10574547387.

It is an arithmetic number, because the mean of its divisors is an integer number (10574547387).

Almost surely, 2^21149094773 is an apocalyptic number.

It is an amenable number.

21149094773 is a deficient number, since it is larger than the sum of its proper divisors (1).

21149094773 is an equidigital number, since it uses as much as digits as its factorization.

21149094773 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 381024, while the sum is 47.

The spelling of 21149094773 in words is "twenty-one billion, one hundred forty-nine million, ninety-four thousand, seven hundred seventy-three".