16440397 has 2 divisors, whose sum is σ = 16440398. Its totient is φ = 16440396.

The previous prime is 16440379. The next prime is 16440407. The reversal of 16440397 is 79304461.

It is a happy number.

Together with previous prime (16440379) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11485321 + 4955076 = 3389^2 + 2226^2 .

It is a cyclic number.

It is not a de Polignac number, because 16440397 - 2¹¹ = 16438349 is a prime.

It is a super-3 number, since 3×16440397³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16440337) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8220198 + 8220199.

It is an arithmetic number, because the mean of its divisors is an integer number (8220199).

Almost surely, 2^16440397 is an apocalyptic number.

It is an amenable number.

16440397 is a deficient number, since it is larger than the sum of its proper divisors (1).

16440397 is an equidigital number, since it uses as much as digits as its factorization.

16440397 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18144, while the sum is 34.

The square root of 16440397 is about 4054.6759426618. The cubic root of 16440397 is about 254.2752559859.

The spelling of 16440397 in words is "sixteen million, four hundred forty thousand, three hundred ninety-seven".