20687997119405 has 54 divisors (see below), whose sum is σ = 31743965588202. Its totient is φ = 12895925602560.

The previous prime is 20687997119401. The next prime is 20687997119417. The reversal of 20687997119405 is 50491179978602.

It can be written as a sum of positive squares in 3 ways, for example, as 55444237156 + 20632552882249 = 235466^2 + 4542307^2 .

It is not a de Polignac number, because 20687997119405 - 2² = 20687997119401 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20687997119401) by changing a digit.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 783118757 + ... + 783145173.

Almost surely, 2^{20687997119405} is an apocalyptic number.

It is an amenable number.

20687997119405 is a deficient number, since it is larger than the sum of its proper divisors (11055968468797).

20687997119405 is an frugal number, since it uses more digits than its factorization.

20687997119405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52875 (or 26440 counting only the distinct ones).

The product of its (nonzero) digits is 68584320, while the sum is 68.

The spelling of 20687997119405 in words is "twenty trillion, six hundred eighty-seven billion, nine hundred ninety-seven million, one hundred nineteen thousand, four hundred five".