16393129981 has 2 divisors, whose sum is σ = 16393129982. Its totient is φ = 16393129980.

The previous prime is 16393129873. The next prime is 16393129997. The reversal of 16393129981 is 18992139361.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13937927481 + 2455202500 = 118059^2 + 49550^2 .

It is a cyclic number.

It is not a de Polignac number, because 16393129981 - 2²⁷ = 16258912253 is a prime.

It is a super-2 number, since 2×16393129981² (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 (16393129481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8196564990 + 8196564991.

It is an arithmetic number, because the mean of its divisors is an integer number (8196564991).

Almost surely, 2^16393129981 is an apocalyptic number.

It is an amenable number.

16393129981 is a deficient number, since it is larger than the sum of its proper divisors (1).

16393129981 is an equidigital number, since it uses as much as digits as its factorization.

16393129981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 629856, while the sum is 52.

The spelling of 16393129981 in words is "sixteen billion, three hundred ninety-three million, one hundred twenty-nine thousand, nine hundred eighty-one".