16264281581 has 2 divisors, whose sum is σ = 16264281582. Its totient is φ = 16264281580.

The previous prime is 16264281563. The next prime is 16264281653. The reversal of 16264281581 is 18518246261.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14296028356 + 1968253225 = 119566^2 + 44365^2 .

It is an emirp because it is prime and its reverse (18518246261) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16264281581 - 2¹⁴ = 16264265197 is a prime.

It is a super-2 number, since 2×16264281581² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16264281281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8132140790 + 8132140791.

It is an arithmetic number, because the mean of its divisors is an integer number (8132140791).

Almost surely, 2^16264281581 is an apocalyptic number.

It is an amenable number.

16264281581 is a deficient number, since it is larger than the sum of its proper divisors (1).

16264281581 is an equidigital number, since it uses as much as digits as its factorization.

16264281581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 184320, while the sum is 44.

The spelling of 16264281581 in words is "sixteen billion, two hundred sixty-four million, two hundred eighty-one thousand, five hundred eighty-one".