16371661 has 2 divisors, whose sum is σ = 16371662. Its totient is φ = 16371660.

The previous prime is 16371659. The next prime is 16371679. The reversal of 16371661 is 16617361.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14976900 + 1394761 = 3870^2 + 1181^2 .

It is a cyclic number.

It is not a de Polignac number, because 16371661 - 2¹ = 16371659 is a prime.

It is a super-3 number, since 3×16371661³ (a number of 23 digits) contains 333 as substring.

Together with 16371659, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16371601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8185830 + 8185831.

It is an arithmetic number, because the mean of its divisors is an integer number (8185831).

Almost surely, 2^16371661 is an apocalyptic number.

It is an amenable number.

16371661 is a deficient number, since it is larger than the sum of its proper divisors (1).

16371661 is an equidigital number, since it uses as much as digits as its factorization.

16371661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4536, while the sum is 31.

The square root of 16371661 is about 4046.1909248082. The cubic root of 16371661 is about 253.9203927267.

It can be divided in two parts, 163 and 71661, that added together give a square (71824 = 268²).

The spelling of 16371661 in words is "sixteen million, three hundred seventy-one thousand, six hundred sixty-one".