20687190681620 has 12 divisors (see below), whose sum is σ = 43443100431444. Its totient is φ = 8274876272640.

The previous prime is 20687190681613. The next prime is 20687190681623. The reversal of 20687190681620 is 2618609178602.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 4531389234436 + 16155801447184 = 2128706^2 + 4019428^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20687190681623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 517179767021 + ... + 517179767060.

It is an arithmetic number, because the mean of its divisors is an integer number (3620258369287).

Almost surely, 2^{20687190681620} is an apocalyptic number.

20687190681620 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20687190681620 is an abundant number, since it is smaller than the sum of its proper divisors (22755909749824).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20687190681620 is a wasteful number, since it uses less digits than its factorization.

20687190681620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1034359534090 (or 1034359534088 counting only the distinct ones).

The product of its (nonzero) digits is 3483648, while the sum is 56.

The spelling of 20687190681620 in words is "twenty trillion, six hundred eighty-seven billion, one hundred ninety million, six hundred eighty-one thousand, six hundred twenty".