21000938453387 has 2 divisors, whose sum is σ = 21000938453388. Its totient is φ = 21000938453386.

The previous prime is 21000938453381. The next prime is 21000938453389. The reversal of 21000938453387 is 78335483900012.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21000938453387 - 2⁴ = 21000938453371 is a prime.

Together with 21000938453389, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21000938453381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500469226693 + 10500469226694.

It is an arithmetic number, because the mean of its divisors is an integer number (10500469226694).

Almost surely, 2^{21000938453387} is an apocalyptic number.

21000938453387 is a deficient number, since it is larger than the sum of its proper divisors (1).

21000938453387 is an equidigital number, since it uses as much as digits as its factorization.

21000938453387 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4354560, while the sum is 53.

The spelling of 21000938453387 in words is "twenty-one trillion, nine hundred thirty-eight million, four hundred fifty-three thousand, three hundred eighty-seven".