20709404855 has 4 divisors (see below), whose sum is σ = 24851285832. Its totient is φ = 16567523880.

The previous prime is 20709404831. The next prime is 20709404873. The reversal of 20709404855 is 55840490702.

It is a happy number.

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

It is not a de Polignac number, because 20709404855 - 2¹⁸ = 20709142711 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2070940481 + ... + 2070940490.

It is an arithmetic number, because the mean of its divisors is an integer number (6212821458).

Almost surely, 2^20709404855 is an apocalyptic number.

20709404855 is a deficient number, since it is larger than the sum of its proper divisors (4141880977).

20709404855 is an equidigital number, since it uses as much as digits as its factorization.

20709404855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4141880976.

The product of its (nonzero) digits is 403200, while the sum is 44.

The spelling of 20709404855 in words is "twenty billion, seven hundred nine million, four hundred four thousand, eight hundred fifty-five".