16398446381 has 12 divisors (see below), whose sum is σ = 17427254100. Its totient is φ = 15427230720.

The previous prime is 16398446353. The next prime is 16398446411. The reversal of 16398446381 is 18364489361.

It can be written as a sum of positive squares in 6 ways, for example, as 2566334281 + 13832112100 = 50659^2 + 117610^2 .

It is a de Polignac number, because none of the positive numbers 2^k-16398446381 is a prime.

It is a super-2 number, since 2×16398446381² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16398446081) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 746645 + ... + 768293.

It is an arithmetic number, because the mean of its divisors is an integer number (1452271175).

Almost surely, 2^16398446381 is an apocalyptic number.

It is an amenable number.

16398446381 is a deficient number, since it is larger than the sum of its proper divisors (1028807719).

16398446381 is a wasteful number, since it uses less digits than its factorization.

16398446381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24304 (or 24287 counting only the distinct ones).

The product of its digits is 2985984, while the sum is 53.

The spelling of 16398446381 in words is "sixteen billion, three hundred ninety-eight million, four hundred forty-six thousand, three hundred eighty-one".