20005591867 has 4 divisors (see below), whose sum is σ = 20203667136. Its totient is φ = 19807516600.

The previous prime is 20005591861. The next prime is 20005591897. The reversal of 20005591867 is 76819550002.

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-20005591867 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20005591861) 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, 99037483 + ... + 99037684.

It is an arithmetic number, because the mean of its divisors is an integer number (5050916784).

Almost surely, 2^20005591867 is an apocalyptic number.

20005591867 is a deficient number, since it is larger than the sum of its proper divisors (198075269).

20005591867 is a wasteful number, since it uses less digits than its factorization.

20005591867 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198075268.

The product of its (nonzero) digits is 151200, while the sum is 43.

The spelling of 20005591867 in words is "twenty billion, five million, five hundred ninety-one thousand, eight hundred sixty-seven".