16897400921 has 2 divisors, whose sum is σ = 16897400922. Its totient is φ = 16897400920.

The previous prime is 16897400881. The next prime is 16897400951. The reversal of 16897400921 is 12900479861.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15822872521 + 1074528400 = 125789^2 + 32780^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16897400921 is a prime.

It is not a weakly prime, because it can be changed into another prime (16897400951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8448700460 + 8448700461.

It is an arithmetic number, because the mean of its divisors is an integer number (8448700461).

Almost surely, 2^16897400921 is an apocalyptic number.

It is an amenable number.

16897400921 is a deficient number, since it is larger than the sum of its proper divisors (1).

16897400921 is an equidigital number, since it uses as much as digits as its factorization.

16897400921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 217728, while the sum is 47.

The spelling of 16897400921 in words is "sixteen billion, eight hundred ninety-seven million, four hundred thousand, nine hundred twenty-one".