20681782140 has 72 divisors (see below), whose sum is σ = 61515829872. Its totient is φ = 5190717440.

The previous prime is 20681782127. The next prime is 20681782181. The reversal of 20681782140 is 4128718602.

It is a happy number.

It is a super-2 number, since 2×20681782140² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 579021 + ... + 613700.

It is an arithmetic number, because the mean of its divisors is an integer number (854386526).

Almost surely, 2^20681782140 is an apocalyptic number.

20681782140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20681782140 is an abundant number, since it is smaller than the sum of its proper divisors (40834047732).

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

20681782140 is a wasteful number, since it uses less digits than its factorization.

20681782140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1192767 (or 1192748 counting only the distinct ones).

The product of its (nonzero) digits is 43008, while the sum is 39.

The spelling of 20681782140 in words is "twenty billion, six hundred eighty-one million, seven hundred eighty-two thousand, one hundred forty".