16642664989 has 2 divisors, whose sum is σ = 16642664990. Its totient is φ = 16642664988.

The previous prime is 16642664977. The next prime is 16642664993. The reversal of 16642664989 is 98946624661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13696020900 + 2946644089 = 117030^2 + 54283^2 .

It is an emirp because it is prime and its reverse (98946624661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16642664989 - 2¹⁷ = 16642533917 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16642664999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8321332494 + 8321332495.

It is an arithmetic number, because the mean of its divisors is an integer number (8321332495).

Almost surely, 2^16642664989 is an apocalyptic number.

It is an amenable number.

16642664989 is a deficient number, since it is larger than the sum of its proper divisors (1).

16642664989 is an equidigital number, since it uses as much as digits as its factorization.

16642664989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 26873856, while the sum is 61.

The spelling of 16642664989 in words is "sixteen billion, six hundred forty-two million, six hundred sixty-four thousand, nine hundred eighty-nine".