21961948373 has 2 divisors, whose sum is σ = 21961948374. Its totient is φ = 21961948372.

The previous prime is 21961948369. The next prime is 21961948381. The reversal of 21961948373 is 37384916912.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17850830449 + 4111117924 = 133607^2 + 64118^2 .

It is a cyclic number.

It is not a de Polignac number, because 21961948373 - 2² = 21961948369 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21961948313) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10980974186 + 10980974187.

It is an arithmetic number, because the mean of its divisors is an integer number (10980974187).

Almost surely, 2^21961948373 is an apocalyptic number.

It is an amenable number.

21961948373 is a deficient number, since it is larger than the sum of its proper divisors (1).

21961948373 is an equidigital number, since it uses as much as digits as its factorization.

21961948373 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1959552, while the sum is 53.

The spelling of 21961948373 in words is "twenty-one billion, nine hundred sixty-one million, nine hundred forty-eight thousand, three hundred seventy-three".