20928371 has 4 divisors (see below), whose sum is σ = 20937744. Its totient is φ = 20919000.

The previous prime is 20928361. The next prime is 20928373. The reversal of 20928371 is 17382902.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 17382902 = 2 ⋅8691451.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20928371 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20928373) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 821 + ... + 6521.

It is an arithmetic number, because the mean of its divisors is an integer number (5234436).

Almost surely, 2^20928371 is an apocalyptic number.

20928371 is a deficient number, since it is larger than the sum of its proper divisors (9373).

20928371 is an equidigital number, since it uses as much as digits as its factorization.

20928371 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9372.

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 20928371 is about 4574.7536545698. The cubic root of 20928371 is about 275.5783793951.

The spelling of 20928371 in words is "twenty million, nine hundred twenty-eight thousand, three hundred seventy-one".