16312421 has 2 divisors, whose sum is σ = 16312422. Its totient is φ = 16312420.

The previous prime is 16312399. The next prime is 16312427. The reversal of 16312421 is 12421361.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15124321 + 1188100 = 3889^2 + 1090^2 .

It is an emirp because it is prime and its reverse (12421361) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16312421 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 16312393 and 16312402.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16312427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8156210 + 8156211.

It is an arithmetic number, because the mean of its divisors is an integer number (8156211).

Almost surely, 2^16312421 is an apocalyptic number.

It is an amenable number.

16312421 is a deficient number, since it is larger than the sum of its proper divisors (1).

16312421 is an equidigital number, since it uses as much as digits as its factorization.

16312421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 288, while the sum is 20.

The square root of 16312421 is about 4038.8638253846. The cubic root of 16312421 is about 253.6137566882.

Adding to 16312421 its reverse (12421361), we get a palindrome (28733782).

The spelling of 16312421 in words is "sixteen million, three hundred twelve thousand, four hundred twenty-one".