16781797 has 2 divisors, whose sum is σ = 16781798. Its totient is φ = 16781796.

The previous prime is 16781753. The next prime is 16781801. The reversal of 16781797 is 79718761.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11826721 + 4955076 = 3439^2 + 2226^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16781797 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16781707) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8390898 + 8390899.

It is an arithmetic number, because the mean of its divisors is an integer number (8390899).

Almost surely, 2^16781797 is an apocalyptic number.

It is an amenable number.

16781797 is a deficient number, since it is larger than the sum of its proper divisors (1).

16781797 is an equidigital number, since it uses as much as digits as its factorization.

16781797 is an evil number, because the sum of its binary digits is even.

The product of its digits is 148176, while the sum is 46.

The square root of 16781797 is about 4096.5591659343. The cubic root of 16781797 is about 256.0232980505.

It can be divided in two parts, 16781 and 797, that added together give a triangular number (17578 = T₁₈₇).

The spelling of 16781797 in words is "sixteen million, seven hundred eighty-one thousand, seven hundred ninety-seven".