20369851867 has 4 divisors (see below), whose sum is σ = 20370143200. Its totient is φ = 20369560536.

The previous prime is 20369851823. The next prime is 20369851889. The reversal of 20369851867 is 76815896302.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a 3-Lehmer number, since φ(20369851867) divides (20369851867-1)³.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20369851867 is a prime.

It is a deceptive number, since it divides R_20369851866.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20369851897) 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, 29134 + ... + 203932.

It is an arithmetic number, because the mean of its divisors is an integer number (5092535800).

Almost surely, 2^20369851867 is an apocalyptic number.

20369851867 is the 116533-rd pentagonal number.

20369851867 is a deficient number, since it is larger than the sum of its proper divisors (291333).

20369851867 is a wasteful number, since it uses less digits than its factorization.

20369851867 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 291332.

The product of its (nonzero) digits is 4354560, while the sum is 55.

The spelling of 20369851867 in words is "twenty billion, three hundred sixty-nine million, eight hundred fifty-one thousand, eight hundred sixty-seven".