16440367997 has 8 divisors (see below), whose sum is σ = 16480536696. Its totient is φ = 16400238592.

The previous prime is 16440367991. The next prime is 16440368029. The reversal of 16440367997 is 79976304461.

It can be written as a sum of positive squares in 4 ways, for example, as 1406175001 + 15034192996 = 37499^2 + 122614^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16440367997 is a prime.

It is a super-3 number, since 3×16440367997³ (a number of 32 digits) contains 333 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 (16440367991) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 936533 + ... + 953925.

It is an arithmetic number, because the mean of its divisors is an integer number (2060067087).

Almost surely, 2^16440367997 is an apocalyptic number.

It is an amenable number.

16440367997 is a deficient number, since it is larger than the sum of its proper divisors (40168699).

16440367997 is a wasteful number, since it uses less digits than its factorization.

16440367997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19647.

The product of its (nonzero) digits is 6858432, while the sum is 56.

The spelling of 16440367997 in words is "sixteen billion, four hundred forty million, three hundred sixty-seven thousand, nine hundred ninety-seven".