16661337401 has 2 divisors, whose sum is σ = 16661337402. Its totient is φ = 16661337400.

The previous prime is 16661337397. The next prime is 16661337431. The reversal of 16661337401 is 10473316661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16389120400 + 272217001 = 128020^2 + 16499^2 .

It is a cyclic number.

It is not a de Polignac number, because 16661337401 - 2² = 16661337397 is a prime.

It is a super-2 number, since 2×16661337401² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (16661337431) 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, 8330668700 + 8330668701.

It is an arithmetic number, because the mean of its divisors is an integer number (8330668701).

Almost surely, 2^16661337401 is an apocalyptic number.

It is an amenable number.

16661337401 is a deficient number, since it is larger than the sum of its proper divisors (1).

16661337401 is an equidigital number, since it uses as much as digits as its factorization.

16661337401 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 54432, while the sum is 38.

The spelling of 16661337401 in words is "sixteen billion, six hundred sixty-one million, three hundred thirty-seven thousand, four hundred one".