20870120856 has 128 divisors (see below), whose sum is σ = 59580722880. Its totient is φ = 6035030016.

The previous prime is 20870120807. The next prime is 20870120861. The reversal of 20870120856 is 65802107802.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 4224820 + ... + 4229756.

Almost surely, 2^20870120856 is an apocalyptic number.

20870120856 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20870120856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29790361440).

20870120856 is an abundant number, since it is smaller than the sum of its proper divisors (38710602024).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20870120856 is a wasteful number, since it uses less digits than its factorization.

20870120856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5773 (or 5769 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 39.

The spelling of 20870120856 in words is "twenty billion, eight hundred seventy million, one hundred twenty thousand, eight hundred fifty-six".