20938478399 has 4 divisors (see below), whose sum is σ = 20941413600. Its totient is φ = 20935543200.

The previous prime is 20938478387. The next prime is 20938478423. The reversal of 20938478399 is 99387483902.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20938478399 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 (20938478339) 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, 1456874 + ... + 1471175.

It is an arithmetic number, because the mean of its divisors is an integer number (5235353400).

Almost surely, 2^20938478399 is an apocalyptic number.

20938478399 is a deficient number, since it is larger than the sum of its proper divisors (2935201).

20938478399 is an equidigital number, since it uses as much as digits as its factorization.

20938478399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2935200.

The product of its (nonzero) digits is 23514624, while the sum is 62.

The spelling of 20938478399 in words is "twenty billion, nine hundred thirty-eight million, four hundred seventy-eight thousand, three hundred ninety-nine".