20981138380 has 24 divisors (see below), whose sum is σ = 44133727680. Its totient is φ = 8378486400.

The previous prime is 20981138369. The next prime is 20981138389. The reversal of 20981138380 is 8383118902.

It is a super-3 number, since 3×20981138380³ (a number of 32 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (20981138389) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 860740 + ... + 884779.

It is an arithmetic number, because the mean of its divisors is an integer number (1838905320).

Almost surely, 2^20981138380 is an apocalyptic number.

20981138380 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20981138380 is an abundant number, since it is smaller than the sum of its proper divisors (23152589300).

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

20981138380 is a wasteful number, since it uses less digits than its factorization.

20981138380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1746129 (or 1746127 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 43.

The spelling of 20981138380 in words is "twenty billion, nine hundred eighty-one million, one hundred thirty-eight thousand, three hundred eighty".