16709621 has 2 divisors, whose sum is σ = 16709622. Its totient is φ = 16709620.

The previous prime is 16709611. The next prime is 16709629. The reversal of 16709621 is 12690761.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15689521 + 1020100 = 3961^2 + 1010^2 .

It is a cyclic number.

It is not a de Polignac number, because 16709621 - 2⁶ = 16709557 is a prime.

It is a super-2 number, since 2×16709621² = 558422867927282, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16709629) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8354810 + 8354811.

It is an arithmetic number, because the mean of its divisors is an integer number (8354811).

Almost surely, 2^16709621 is an apocalyptic number.

It is an amenable number.

16709621 is a deficient number, since it is larger than the sum of its proper divisors (1).

16709621 is an equidigital number, since it uses as much as digits as its factorization.

16709621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4536, while the sum is 32.

The square root of 16709621 is about 4087.7403293262. The cubic root of 16709621 is about 255.6557312862.

The spelling of 16709621 in words is "sixteen million, seven hundred nine thousand, six hundred twenty-one".