16249421 has 2 divisors, whose sum is σ = 16249422. Its totient is φ = 16249420.

The previous prime is 16249411. The next prime is 16249423. The reversal of 16249421 is 12494261.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12524521 + 3724900 = 3539^2 + 1930^2 .

It is a cyclic number.

It is not a de Polignac number, because 16249421 - 2²² = 12055117 is a prime.

Together with 16249423, 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 (16249423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8124710 + 8124711.

It is an arithmetic number, because the mean of its divisors is an integer number (8124711).

Almost surely, 2^16249421 is an apocalyptic number.

It is an amenable number.

16249421 is a deficient number, since it is larger than the sum of its proper divisors (1).

16249421 is an equidigital number, since it uses as much as digits as its factorization.

16249421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3456, while the sum is 29.

The square root of 16249421 is about 4031.0570573982. The cubic root of 16249421 is about 253.2868426152.

The spelling of 16249421 in words is "sixteen million, two hundred forty-nine thousand, four hundred twenty-one".