20438917 has 4 divisors (see below), whose sum is σ = 20626540. Its totient is φ = 20251296.

The previous prime is 20438909. The next prime is 20438923. The reversal of 20438917 is 71983402.

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

It can be written as a sum of positive squares in 2 ways, for example, as 16434916 + 4004001 = 4054^2 + 2001^2 .

It is a cyclic number.

It is not a de Polignac number, because 20438917 - 2³ = 20438909 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 (20438617) 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, 93648 + ... + 93865.

It is an arithmetic number, because the mean of its divisors is an integer number (5156635).

Almost surely, 2^20438917 is an apocalyptic number.

It is an amenable number.

20438917 is a deficient number, since it is larger than the sum of its proper divisors (187623).

20438917 is a wasteful number, since it uses less digits than its factorization.

20438917 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 187622.

The product of its (nonzero) digits is 12096, while the sum is 34.

The square root of 20438917 is about 4520.9420478480. The cubic root of 20438917 is about 273.4130838411.

The spelling of 20438917 in words is "twenty million, four hundred thirty-eight thousand, nine hundred seventeen".