20806156140 has 384 divisors, whose sum is σ = 76082872320. Its totient is φ = 4121779200.

The previous prime is 20806156121. The next prime is 20806156187. The reversal of 20806156140 is 4165160802.

It is a super-2 number, since 2×20806156140² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 11119405 + ... + 11121275.

It is an arithmetic number, because the mean of its divisors is an integer number (198132480).

Almost surely, 2^20806156140 is an apocalyptic number.

20806156140 is a gapful number since it is divisible by the number (20) 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 20806156140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38041436160).

20806156140 is an abundant number, since it is smaller than the sum of its proper divisors (55276716180).

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

20806156140 is a wasteful number, since it uses less digits than its factorization.

20806156140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2013 (or 2011 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 33.

The spelling of 20806156140 in words is "twenty billion, eight hundred six million, one hundred fifty-six thousand, one hundred forty".