16978651 has 2 divisors, whose sum is σ = 16978652. Its totient is φ = 16978650.

The previous prime is 16978649. The next prime is 16978657. The reversal of 16978651 is 15687961.

It is a happy number.

It is a weak prime.

It is an emirp because it is prime and its reverse (15687961) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16978651 - 2¹ = 16978649 is a prime.

Together with 16978649, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 16978598 and 16978607.

It is not a weakly prime, because it can be changed into another prime (16978657) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8489325 + 8489326.

It is an arithmetic number, because the mean of its divisors is an integer number (8489326).

Almost surely, 2^16978651 is an apocalyptic number.

16978651 is a deficient number, since it is larger than the sum of its proper divisors (1).

16978651 is an equidigital number, since it uses as much as digits as its factorization.

16978651 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 90720, while the sum is 43.

The square root of 16978651 is about 4120.5158657624. The cubic root of 16978651 is about 257.0204781131.

The spelling of 16978651 in words is "sixteen million, nine hundred seventy-eight thousand, six hundred fifty-one".