16005379681 has 2 divisors, whose sum is σ = 16005379682. Its totient is φ = 16005379680.

The previous prime is 16005379651. The next prime is 16005379723. The reversal of 16005379681 is 18697350061.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14814784656 + 1190595025 = 121716^2 + 34505^2 .

It is a cyclic number.

It is not a de Polignac number, because 16005379681 - 2⁷ = 16005379553 is a prime.

It is a super-2 number, since 2×16005379681² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (16005379651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8002689840 + 8002689841.

It is an arithmetic number, because the mean of its divisors is an integer number (8002689841).

Almost surely, 2^16005379681 is an apocalyptic number.

It is an amenable number.

16005379681 is a deficient number, since it is larger than the sum of its proper divisors (1).

16005379681 is an equidigital number, since it uses as much as digits as its factorization.

16005379681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 272160, while the sum is 46.

The spelling of 16005379681 in words is "sixteen billion, five million, three hundred seventy-nine thousand, six hundred eighty-one".