20876021 has 4 divisors (see below), whose sum is σ = 21071232. Its totient is φ = 20680812.

The previous prime is 20875991. The next prime is 20876047. The reversal of 20876021 is 12067802.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12067802 = 2 ⋅6033901.

It is a cyclic number.

It is not a de Polignac number, because 20876021 - 2¹⁴ = 20859637 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20876081) 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, 97445 + ... + 97658.

It is an arithmetic number, because the mean of its divisors is an integer number (5267808).

Almost surely, 2^20876021 is an apocalyptic number.

It is an amenable number.

20876021 is a deficient number, since it is larger than the sum of its proper divisors (195211).

20876021 is a wasteful number, since it uses less digits than its factorization.

20876021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195210.

The product of its (nonzero) digits is 1344, while the sum is 26.

The square root of 20876021 is about 4569.0284525269. The cubic root of 20876021 is about 275.3484112864.

The spelling of 20876021 in words is "twenty million, eight hundred seventy-six thousand, twenty-one".