20861903859 has 4 divisors (see below), whose sum is σ = 27815871816. Its totient is φ = 13907935904.

The previous prime is 20861903813. The next prime is 20861903861. The reversal of 20861903859 is 95830916802.

It is a happy number.

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 20861903859 - 2⁷ = 20861903731 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20861903899) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3476983974 + ... + 3476983979.

It is an arithmetic number, because the mean of its divisors is an integer number (6953967954).

Almost surely, 2^20861903859 is an apocalyptic number.

20861903859 is a deficient number, since it is larger than the sum of its proper divisors (6953967957).

20861903859 is an equidigital number, since it uses as much as digits as its factorization.

20861903859 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6953967956.

The product of its (nonzero) digits is 933120, while the sum is 51.

The spelling of 20861903859 in words is "twenty billion, eight hundred sixty-one million, nine hundred three thousand, eight hundred fifty-nine".