20438390 has 48 divisors (see below), whose sum is σ = 43658352. Its totient is φ = 6866496.

The previous prime is 20438389. The next prime is 20438413. The reversal of 20438390 is 9383402.

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 25577 + ... + 26363.

It is an arithmetic number, because the mean of its divisors is an integer number (909549).

Almost surely, 2^20438390 is an apocalyptic number.

20438390 is an abundant number, since it is smaller than the sum of its proper divisors (23219962).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20438390 is a wasteful number, since it uses less digits than its factorization.

20438390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 861 (or 854 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 29.

The square root of 20438390 is about 4520.8837631596. The cubic root of 20438390 is about 273.4107339134.

The spelling of 20438390 in words is "twenty million, four hundred thirty-eight thousand, three hundred ninety".