20639206140 has 48 divisors (see below), whose sum is σ = 66045460992. Its totient is φ = 4717532736.

The previous prime is 20639206121. The next prime is 20639206213. The reversal of 20639206140 is 4160293602.

It is a super-3 number, since 3×20639206140³ (a number of 32 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24570064 + ... + 24570903.

It is an arithmetic number, because the mean of its divisors is an integer number (1375947104).

Almost surely, 2^20639206140 is an apocalyptic number.

20639206140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20639206140 is an abundant number, since it is smaller than the sum of its proper divisors (45406254852).

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

20639206140 is a wasteful number, since it uses less digits than its factorization.

20639206140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49140986 (or 49140984 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 33.

Adding to 20639206140 its reverse (4160293602), we get a palindrome (24799499742).

The spelling of 20639206140 in words is "twenty billion, six hundred thirty-nine million, two hundred six thousand, one hundred forty".