20873421 has 12 divisors (see below), whose sum is σ = 30514848. Its totient is φ = 13747464.

The previous prime is 20873393. The next prime is 20873423. The reversal of 20873421 is 12437802.

It is not a de Polignac number, because 20873421 - 2⁵ = 20873389 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20873423) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 13225 + ... + 14718.

It is an arithmetic number, because the mean of its divisors is an integer number (2542904).

Almost surely, 2^20873421 is an apocalyptic number.

It is an amenable number.

20873421 is a deficient number, since it is larger than the sum of its proper divisors (9641427).

20873421 is a wasteful number, since it uses less digits than its factorization.

20873421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28032 (or 28029 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 20873421 is about 4568.7439192846. The cubic root of 20873421 is about 275.3369797403.

The spelling of 20873421 in words is "twenty million, eight hundred seventy-three thousand, four hundred twenty-one".