16664261 has 2 divisors, whose sum is σ = 16664262. Its totient is φ = 16664260.

The previous prime is 16664239. The next prime is 16664317. The reversal of 16664261 is 16246661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16048036 + 616225 = 4006^2 + 785^2 .

It is a cyclic number.

It is not a de Polignac number, because 16664261 - 2¹⁴ = 16647877 is a prime.

It is a super-2 number, since 2×16664261² = 555395189352242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16664231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8332130 + 8332131.

It is an arithmetic number, because the mean of its divisors is an integer number (8332131).

Almost surely, 2^16664261 is an apocalyptic number.

It is an amenable number.

16664261 is a deficient number, since it is larger than the sum of its proper divisors (1).

16664261 is an equidigital number, since it uses as much as digits as its factorization.

16664261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10368, while the sum is 32.

The square root of 16664261 is about 4082.1882612148. The cubic root of 16664261 is about 255.4241869728.

The spelling of 16664261 in words is "sixteen million, six hundred sixty-four thousand, two hundred sixty-one".