16398765 has 12 divisors (see below), whose sum is σ = 28424604. Its totient is φ = 8745984.

The previous prime is 16398743. The next prime is 16398769. The reversal of 16398765 is 56789361.

It is a happy number.

16398765 is a `hidden beast` number, since 1 + 639 + 8 + 7 + 6 + 5 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 2064969 + 14333796 = 1437^2 + 3786^2 .

It is not a de Polignac number, because 16398765 - 2¹² = 16394669 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45), and also a Moran number because the ratio is a prime number: 364417 = 16398765 / (1 + 6 + 3 + 9 + 8 + 7 + 6 + 5).

It is a self number, because there is not a number n which added to its sum of digits gives 16398765.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16398769) 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, 182164 + ... + 182253.

It is an arithmetic number, because the mean of its divisors is an integer number (2368717).

Almost surely, 2^16398765 is an apocalyptic number.

16398765 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

16398765 is a deficient number, since it is larger than the sum of its proper divisors (12025839).

16398765 is a wasteful number, since it uses less digits than its factorization.

16398765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 364428 (or 364425 counting only the distinct ones).

The product of its digits is 272160, while the sum is 45.

The square root of 16398765 is about 4049.5388626361. The cubic root of 16398765 is about 254.0604409041.

It can be divided in two parts, 1639 and 8765, that added together give a square (10404 = 102²).

The spelling of 16398765 in words is "sixteen million, three hundred ninety-eight thousand, seven hundred sixty-five".