16978361 has 4 divisors (see below), whose sum is σ = 16993572. Its totient is φ = 16963152.

The previous prime is 16978349. The next prime is 16978373. The reversal of 16978361 is 16387961.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16387961 = 139 ⋅117899.

It is an interprime number because it is at equal distance from previous prime (16978349) and next prime (16978373).

It can be written as a sum of positive squares in 2 ways, for example, as 3728761 + 13249600 = 1931^2 + 3640^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16978361 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16978331) 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, 5786 + ... + 8211.

It is an arithmetic number, because the mean of its divisors is an integer number (4248393).

Almost surely, 2^16978361 is an apocalyptic number.

It is an amenable number.

16978361 is a deficient number, since it is larger than the sum of its proper divisors (15211).

16978361 is a wasteful number, since it uses less digits than its factorization.

16978361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15210.

The product of its digits is 54432, while the sum is 41.

The square root of 16978361 is about 4120.4806758435. The cubic root of 16978361 is about 257.0190147781.

The spelling of 16978361 in words is "sixteen million, nine hundred seventy-eight thousand, three hundred sixty-one".