20476917787 has 4 divisors (see below), whose sum is σ = 20501679096. Its totient is φ = 20452156480.

The previous prime is 20476917763. The next prime is 20476917859. The reversal of 20476917787 is 78771967402.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20476917787 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20476917737) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12379414 + ... + 12381067.

It is an arithmetic number, because the mean of its divisors is an integer number (5125419774).

Almost surely, 2^20476917787 is an apocalyptic number.

20476917787 is a deficient number, since it is larger than the sum of its proper divisors (24761309).

20476917787 is an equidigital number, since it uses as much as digits as its factorization.

20476917787 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24761308.

The product of its (nonzero) digits is 8297856, while the sum is 58.

The spelling of 20476917787 in words is "twenty billion, four hundred seventy-six million, nine hundred seventeen thousand, seven hundred eighty-seven".