16721245787 has 2 divisors, whose sum is σ = 16721245788. Its totient is φ = 16721245786.

The previous prime is 16721245711. The next prime is 16721245813. The reversal of 16721245787 is 78754212761.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 16721245787 - 2⁸ = 16721245531 is a prime.

It is not a weakly prime, because it can be changed into another prime (16721245087) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8360622893 + 8360622894.

It is an arithmetic number, because the mean of its divisors is an integer number (8360622894).

Almost surely, 2^16721245787 is an apocalyptic number.

16721245787 is a deficient number, since it is larger than the sum of its proper divisors (1).

16721245787 is an equidigital number, since it uses as much as digits as its factorization.

16721245787 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1317120, while the sum is 50.

The spelling of 16721245787 in words is "sixteen billion, seven hundred twenty-one million, two hundred forty-five thousand, seven hundred eighty-seven".