16978089 has 4 divisors (see below), whose sum is σ = 22637456. Its totient is φ = 11318724.

The previous prime is 16978061. The next prime is 16978097. The reversal of 16978089 is 98087961.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 98087961 = 3 ⋅32695987.

It is not a de Polignac number, because 16978089 - 2⁵ = 16978057 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16978009) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2829679 + ... + 2829684.

It is an arithmetic number, because the mean of its divisors is an integer number (5659364).

Almost surely, 2^16978089 is an apocalyptic number.

It is an amenable number.

16978089 is a deficient number, since it is larger than the sum of its proper divisors (5659367).

16978089 is an equidigital number, since it uses as much as digits as its factorization.

16978089 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5659366.

The product of its (nonzero) digits is 217728, while the sum is 48.

The square root of 16978089 is about 4120.4476698534. The cubic root of 16978089 is about 257.0176422556.

The spelling of 16978089 in words is "sixteen million, nine hundred seventy-eight thousand, eighty-nine".