20340021 has 8 divisors (see below), whose sum is σ = 29206240. Its totient is φ = 12516912.

The previous prime is 20340011. The next prime is 20340029. The reversal of 20340021 is 12004302.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20340021 - 2¹⁴ = 20323637 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20339979 and 20340006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20340029) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 260731 + ... + 260808.

It is an arithmetic number, because the mean of its divisors is an integer number (3650780).

Almost surely, 2^20340021 is an apocalyptic number.

It is an amenable number.

20340021 is a deficient number, since it is larger than the sum of its proper divisors (8866219).

20340021 is a wasteful number, since it uses less digits than its factorization.

20340021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 521555.

The product of its (nonzero) digits is 48, while the sum is 12.

The square root of 20340021 is about 4509.9912416766. The cubic root of 20340021 is about 272.9713906876.

Adding to 20340021 its reverse (12004302), we get a palindrome (32344323).

The spelling of 20340021 in words is "twenty million, three hundred forty thousand, twenty-one".