20147661663 has 4 divisors (see below), whose sum is σ = 26863548888. Its totient is φ = 13431774440.

The previous prime is 20147661661. The next prime is 20147661671. The reversal of 20147661663 is 36616674102.

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

It is a cyclic number.

It is not a de Polignac number, because 20147661663 - 2¹ = 20147661661 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20147661661) 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, 3357943608 + ... + 3357943613.

It is an arithmetic number, because the mean of its divisors is an integer number (6715887222).

Almost surely, 2^20147661663 is an apocalyptic number.

20147661663 is a deficient number, since it is larger than the sum of its proper divisors (6715887225).

20147661663 is an equidigital number, since it uses as much as digits as its factorization.

20147661663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6715887224.

The product of its (nonzero) digits is 217728, while the sum is 42.

The spelling of 20147661663 in words is "twenty billion, one hundred forty-seven million, six hundred sixty-one thousand, six hundred sixty-three".