16993765 has 4 divisors (see below), whose sum is σ = 20392524. Its totient is φ = 13595008.

The previous prime is 16993759. The next prime is 16993777. The reversal of 16993765 is 56739961.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56739961 = 6229 ⋅9109.

It can be written as a sum of positive squares in 2 ways, for example, as 9928801 + 7064964 = 3151^2 + 2658^2 .

It is a cyclic number.

It is not a de Polignac number, because 16993765 - 2⁹ = 16993253 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1699372 + ... + 1699381.

It is an arithmetic number, because the mean of its divisors is an integer number (5098131).

Almost surely, 2^16993765 is an apocalyptic number.

It is an amenable number.

16993765 is a deficient number, since it is larger than the sum of its proper divisors (3398759).

16993765 is an equidigital number, since it uses as much as digits as its factorization.

16993765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3398758.

The product of its digits is 306180, while the sum is 46.

The square root of 16993765 is about 4122.3494514658. The cubic root of 16993765 is about 257.0967200441.

The spelling of 16993765 in words is "sixteen million, nine hundred ninety-three thousand, seven hundred sixty-five".