16402621 has 2 divisors, whose sum is σ = 16402622. Its totient is φ = 16402620.

The previous prime is 16402619. The next prime is 16402667. The reversal of 16402621 is 12620461.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16402500 + 121 = 4050^2 + 11^2 .

It is a cyclic number.

It is not a de Polignac number, because 16402621 - 2¹ = 16402619 is a prime.

Together with 16402619, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 16402592 and 16402601.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16402121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8201310 + 8201311.

It is an arithmetic number, because the mean of its divisors is an integer number (8201311).

Almost surely, 2^16402621 is an apocalyptic number.

It is an amenable number.

16402621 is a deficient number, since it is larger than the sum of its proper divisors (1).

16402621 is an equidigital number, since it uses as much as digits as its factorization.

16402621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 16402621 is about 4050.0149382441. The cubic root of 16402621 is about 254.0803525720.

The spelling of 16402621 in words is "sixteen million, four hundred two thousand, six hundred twenty-one".