21120221185787 has 2 divisors, whose sum is σ = 21120221185788. Its totient is φ = 21120221185786.

The previous prime is 21120221185783. The next prime is 21120221185837. The reversal of 21120221185787 is 78758112202112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21120221185787 - 2² = 21120221185783 is a prime.

It is not a weakly prime, because it can be changed into another prime (21120221185783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560110592893 + 10560110592894.

It is an arithmetic number, because the mean of its divisors is an integer number (10560110592894).

Almost surely, 2^{21120221185787} is an apocalyptic number.

21120221185787 is a deficient number, since it is larger than the sum of its proper divisors (1).

21120221185787 is an equidigital number, since it uses as much as digits as its factorization.

21120221185787 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 250880, while the sum is 47.

Adding to 21120221185787 its reverse (78758112202112), we get a palindrome (99878333387899).

The spelling of 21120221185787 in words is "twenty-one trillion, one hundred twenty billion, two hundred twenty-one million, one hundred eighty-five thousand, seven hundred eighty-seven".