20490395638 has 8 divisors (see below), whose sum is σ = 30737769480. Its totient is φ = 10244472480.

The previous prime is 20490395633. The next prime is 20490395659. The reversal of 20490395638 is 83659309402.

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

It is a junction number, because it is equal to n+sod(n) for n = 20490395591 and 20490395600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20490395633) 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, 326643 + ... + 384286.

It is an arithmetic number, because the mean of its divisors is an integer number (3842221185).

Almost surely, 2^20490395638 is an apocalyptic number.

20490395638 is a deficient number, since it is larger than the sum of its proper divisors (10247373842).

20490395638 is a wasteful number, since it uses less digits than its factorization.

20490395638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 725342.

The product of its (nonzero) digits is 1399680, while the sum is 49.

The spelling of 20490395638 in words is "twenty billion, four hundred ninety million, three hundred ninety-five thousand, six hundred thirty-eight".