20998345 has 4 divisors (see below), whose sum is σ = 25198020. Its totient is φ = 16798672.

The previous prime is 20998303. The next prime is 20998387. The reversal of 20998345 is 54389902.

It is a happy number.

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

It is an interprime number because it is at equal distance from previous prime (20998303) and next prime (20998387).

It can be written as a sum of positive squares in 2 ways, for example, as 14907321 + 6091024 = 3861^2 + 2468^2 .

It is a cyclic number.

It is not a de Polignac number, because 20998345 - 2¹⁵ = 20965577 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20998298 and 20998307.

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, 2099830 + ... + 2099839.

It is an arithmetic number, because the mean of its divisors is an integer number (6299505).

Almost surely, 2^20998345 is an apocalyptic number.

It is an amenable number.

20998345 is a deficient number, since it is larger than the sum of its proper divisors (4199675).

20998345 is an equidigital number, since it uses as much as digits as its factorization.

20998345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4199674.

The product of its (nonzero) digits is 77760, while the sum is 40.

The square root of 20998345 is about 4582.3951160938. The cubic root of 20998345 is about 275.8851697977.

The spelling of 20998345 in words is "twenty million, nine hundred ninety-eight thousand, three hundred forty-five".