16335425221 has 2 divisors, whose sum is σ = 16335425222. Its totient is φ = 16335425220.

The previous prime is 16335425201. The next prime is 16335425243. The reversal of 16335425221 is 12252453361.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9917172225 + 6418252996 = 99585^2 + 80114^2 .

It is a cyclic number.

It is not a de Polignac number, because 16335425221 - 2⁵ = 16335425189 is a prime.

It is a super-2 number, since 2×16335425221² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16335425201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8167712610 + 8167712611.

It is an arithmetic number, because the mean of its divisors is an integer number (8167712611).

Almost surely, 2^16335425221 is an apocalyptic number.

It is an amenable number.

16335425221 is a deficient number, since it is larger than the sum of its proper divisors (1).

16335425221 is an equidigital number, since it uses as much as digits as its factorization.

16335425221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 43200, while the sum is 34.

Adding to 16335425221 its reverse (12252453361), we get a palindrome (28587878582).

The spelling of 16335425221 in words is "sixteen billion, three hundred thirty-five million, four hundred twenty-five thousand, two hundred twenty-one".