16397297381 has 4 divisors (see below), whose sum is σ = 16397707200. Its totient is φ = 16396887564.

The previous prime is 16397297377. The next prime is 16397297393. The reversal of 16397297381 is 18379279361.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 16397297381 - 2² = 16397297377 is a prime.

It is a super-2 number, since 2×16397297381² (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 (16397297341) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 137501 + ... + 227378.

It is an arithmetic number, because the mean of its divisors is an integer number (4099426800).

Almost surely, 2^16397297381 is an apocalyptic number.

It is an amenable number.

16397297381 is a deficient number, since it is larger than the sum of its proper divisors (409819).

16397297381 is an equidigital number, since it uses as much as digits as its factorization.

16397297381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 409818.

The product of its digits is 3429216, while the sum is 56.

The spelling of 16397297381 in words is "sixteen billion, three hundred ninety-seven million, two hundred ninety-seven thousand, three hundred eighty-one".