21365001103987 has 2 divisors, whose sum is σ = 21365001103988. Its totient is φ = 21365001103986.

The previous prime is 21365001103951. The next prime is 21365001104143. The reversal of 21365001103987 is 78930110056312.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21365001103987 is a prime.

It is not a weakly prime, because it can be changed into another prime (21365001103937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10682500551993 + 10682500551994.

It is an arithmetic number, because the mean of its divisors is an integer number (10682500551994).

Almost surely, 2^{21365001103987} is an apocalyptic number.

21365001103987 is a deficient number, since it is larger than the sum of its proper divisors (1).

21365001103987 is an equidigital number, since it uses as much as digits as its factorization.

21365001103987 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 272160, while the sum is 46.

The spelling of 21365001103987 in words is "twenty-one trillion, three hundred sixty-five billion, one million, one hundred three thousand, nine hundred eighty-seven".