16870621 has 2 divisors, whose sum is σ = 16870622. Its totient is φ = 16870620.

The previous prime is 16870559. The next prime is 16870627. The reversal of 16870621 is 12607861.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11464996 + 5405625 = 3386^2 + 2325^2 .

It is a cyclic number.

It is not a de Polignac number, because 16870621 - 2⁷ = 16870493 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16870627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8435310 + 8435311.

It is an arithmetic number, because the mean of its divisors is an integer number (8435311).

Almost surely, 2^16870621 is an apocalyptic number.

It is an amenable number.

16870621 is a deficient number, since it is larger than the sum of its proper divisors (1).

16870621 is an equidigital number, since it uses as much as digits as its factorization.

16870621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 16870621 is about 4107.3861518002. The cubic root of 16870621 is about 256.4742034609.

The spelling of 16870621 in words is "sixteen million, eight hundred seventy thousand, six hundred twenty-one".