20938478387 has 2 divisors, whose sum is σ = 20938478388. Its totient is φ = 20938478386.

The previous prime is 20938478357. The next prime is 20938478423. The reversal of 20938478387 is 78387483902.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20938478387 - 2¹⁴ = 20938462003 is a prime.

It is a super-2 number, since 2×20938478387² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20938478347) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10469239193 + 10469239194.

It is an arithmetic number, because the mean of its divisors is an integer number (10469239194).

Almost surely, 2^20938478387 is an apocalyptic number.

20938478387 is a deficient number, since it is larger than the sum of its proper divisors (1).

20938478387 is an equidigital number, since it uses as much as digits as its factorization.

20938478387 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16257024, while the sum is 59.

The spelling of 20938478387 in words is "twenty billion, nine hundred thirty-eight million, four hundred seventy-eight thousand, three hundred eighty-seven".