20938478461 has 2 divisors, whose sum is σ = 20938478462. Its totient is φ = 20938478460.

The previous prime is 20938478447. The next prime is 20938478479. The reversal of 20938478461 is 16487483902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17184588100 + 3753890361 = 131090^2 + 61269^2 .

It is a cyclic number.

It is not a de Polignac number, because 20938478461 - 2¹⁷ = 20938347389 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20938478399 and 20938478408.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20938478861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10469239230 + 10469239231.

It is an arithmetic number, because the mean of its divisors is an integer number (10469239231).

Almost surely, 2^20938478461 is an apocalyptic number.

It is an amenable number.

20938478461 is a deficient number, since it is larger than the sum of its proper divisors (1).

20938478461 is an equidigital number, since it uses as much as digits as its factorization.

20938478461 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2322432, while the sum is 52.

The spelling of 20938478461 in words is "twenty billion, nine hundred thirty-eight million, four hundred seventy-eight thousand, four hundred sixty-one".