16421597 has 2 divisors, whose sum is σ = 16421598. Its totient is φ = 16421596.

The previous prime is 16421593. The next prime is 16421623. The reversal of 16421597 is 79512461.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15007876 + 1413721 = 3874^2 + 1189^2 .

It is a cyclic number.

It is not a de Polignac number, because 16421597 - 2² = 16421593 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16421593) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8210798 + 8210799.

It is an arithmetic number, because the mean of its divisors is an integer number (8210799).

Almost surely, 2^16421597 is an apocalyptic number.

It is an amenable number.

16421597 is a deficient number, since it is larger than the sum of its proper divisors (1).

16421597 is an equidigital number, since it uses as much as digits as its factorization.

16421597 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15120, while the sum is 35.

The square root of 16421597 is about 4052.3569684814. The cubic root of 16421597 is about 254.1782956726.

The spelling of 16421597 in words is "sixteen million, four hundred twenty-one thousand, five hundred ninety-seven".