16855801997 has 2 divisors, whose sum is σ = 16855801998. Its totient is φ = 16855801996.

The previous prime is 16855801927. The next prime is 16855802069. The reversal of 16855801997 is 79910855861.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9529469161 + 7326332836 = 97619^2 + 85594^2 .

It is a cyclic number.

It is not a de Polignac number, because 16855801997 - 2¹² = 16855797901 is a prime.

It is a super-3 number, since 3×16855801997³ (a number of 32 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16855801927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8427900998 + 8427900999.

It is an arithmetic number, because the mean of its divisors is an integer number (8427900999).

Almost surely, 2^16855801997 is an apocalyptic number.

It is an amenable number.

16855801997 is a deficient number, since it is larger than the sum of its proper divisors (1).

16855801997 is an equidigital number, since it uses as much as digits as its factorization.

16855801997 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5443200, while the sum is 59.

The spelling of 16855801997 in words is "sixteen billion, eight hundred fifty-five million, eight hundred one thousand, nine hundred ninety-seven".