16451978999 has 2 divisors, whose sum is σ = 16451979000. Its totient is φ = 16451978998.

The previous prime is 16451978971. The next prime is 16451979001. The reversal of 16451978999 is 99987915461.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 16451978999 - 2⁸ = 16451978743 is a prime.

It is a super-2 number, since 2×16451978999² (a number of 21 digits) contains 22 as substring.

Together with 16451979001, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16451978909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8225989499 + 8225989500.

It is an arithmetic number, because the mean of its divisors is an integer number (8225989500).

Almost surely, 2^16451978999 is an apocalyptic number.

16451978999 is a deficient number, since it is larger than the sum of its proper divisors (1).

16451978999 is an equidigital number, since it uses as much as digits as its factorization.

16451978999 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 44089920, while the sum is 68.

The spelling of 16451978999 in words is "sixteen billion, four hundred fifty-one million, nine hundred seventy-eight thousand, nine hundred ninety-nine".