21000120999373 has 2 divisors, whose sum is σ = 21000120999374. Its totient is φ = 21000120999372.

The previous prime is 21000120999367. The next prime is 21000120999427. The reversal of 21000120999373 is 37399902100012.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20491356920644 + 508764078729 = 4526738^2 + 713277^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21000120999373 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21000120999343) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500060499686 + 10500060499687.

It is an arithmetic number, because the mean of its divisors is an integer number (10500060499687).

Almost surely, 2^{21000120999373} is an apocalyptic number.

It is an amenable number.

21000120999373 is a deficient number, since it is larger than the sum of its proper divisors (1).

21000120999373 is an equidigital number, since it uses as much as digits as its factorization.

21000120999373 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 183708, while the sum is 46.

The spelling of 21000120999373 in words is "twenty-one trillion, one hundred twenty million, nine hundred ninety-nine thousand, three hundred seventy-three".