20787005545 has 4 divisors (see below), whose sum is σ = 24944406660. Its totient is φ = 16629604432.

The previous prime is 20787005521. The next prime is 20787005567. The reversal of 20787005545 is 54550078702.

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

It can be written as a sum of positive squares in 2 ways, for example, as 16129762009 + 4657243536 = 127003^2 + 68244^2 .

It is a cyclic number.

It is not a de Polignac number, because 20787005545 - 2¹⁹ = 20786481257 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2078700550 + ... + 2078700559.

It is an arithmetic number, because the mean of its divisors is an integer number (6236101665).

Almost surely, 2^20787005545 is an apocalyptic number.

It is an amenable number.

20787005545 is a deficient number, since it is larger than the sum of its proper divisors (4157401115).

20787005545 is an equidigital number, since it uses as much as digits as its factorization.

20787005545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4157401114.

The product of its (nonzero) digits is 392000, while the sum is 43.

The spelling of 20787005545 in words is "twenty billion, seven hundred eighty-seven million, five thousand, five hundred forty-five".