20918769 has 16 divisors (see below), whose sum is σ = 29466624. Its totient is φ = 13179600.

The previous prime is 20918767. The next prime is 20918771. The reversal of 20918769 is 96781902.

It is an interprime number because it is at equal distance from previous prime (20918767) and next prime (20918771).

It is not a de Polignac number, because 20918769 - 2¹ = 20918767 is a prime.

It is a super-2 number, since 2×20918769² = 875189792950722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20918769.

It is not an unprimeable number, because it can be changed into a prime (20918767) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1384 + ... + 6614.

It is an arithmetic number, because the mean of its divisors is an integer number (1841664).

Almost surely, 2^20918769 is an apocalyptic number.

It is an amenable number.

20918769 is a deficient number, since it is larger than the sum of its proper divisors (8547855).

20918769 is a wasteful number, since it uses less digits than its factorization.

20918769 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5308.

The product of its (nonzero) digits is 54432, while the sum is 42.

The square root of 20918769 is about 4573.7040787528. The cubic root of 20918769 is about 275.5362275496.

The spelling of 20918769 in words is "twenty million, nine hundred eighteen thousand, seven hundred sixty-nine".