20117749 has 4 divisors (see below), whose sum is σ = 21301164. Its totient is φ = 18934336.

The previous prime is 20117737. The next prime is 20117759. The reversal of 20117749 is 94771102.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9922500 + 10195249 = 3150^2 + 3193^2 .

It is a cyclic number.

It is not a de Polignac number, because 20117749 - 2⁵ = 20117717 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20117749.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20117719) 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, 591682 + ... + 591715.

It is an arithmetic number, because the mean of its divisors is an integer number (5325291).

Almost surely, 2^20117749 is an apocalyptic number.

It is an amenable number.

20117749 is a deficient number, since it is larger than the sum of its proper divisors (1183415).

20117749 is a wasteful number, since it uses less digits than its factorization.

20117749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1183414.

The product of its (nonzero) digits is 3528, while the sum is 31.

The square root of 20117749 is about 4485.2813735595. The cubic root of 20117749 is about 271.9734195840.

The spelling of 20117749 in words is "twenty million, one hundred seventeen thousand, seven hundred forty-nine".