16287421 has 2 divisors, whose sum is σ = 16287422. Its totient is φ = 16287420.

The previous prime is 16287419. The next prime is 16287443. The reversal of 16287421 is 12478261.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8916196 + 7371225 = 2986^2 + 2715^2 .

It is an emirp because it is prime and its reverse (12478261) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16287421 - 2¹ = 16287419 is a prime.

Together with 16287419, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16287451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8143710 + 8143711.

It is an arithmetic number, because the mean of its divisors is an integer number (8143711).

Almost surely, 2^16287421 is an apocalyptic number.

It is an amenable number.

16287421 is a deficient number, since it is larger than the sum of its proper divisors (1).

16287421 is an equidigital number, since it uses as much as digits as its factorization.

16287421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5376, while the sum is 31.

The square root of 16287421 is about 4035.7677088752. The cubic root of 16287421 is about 253.4841297883.

The spelling of 16287421 in words is "sixteen million, two hundred eighty-seven thousand, four hundred twenty-one".