20519927981 has 8 divisors (see below), whose sum is σ = 23474876160. Its totient is φ = 17570862288.

The previous prime is 20519927977. The next prime is 20519927983. The reversal of 20519927981 is 18972991502.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20519927981 - 2² = 20519927977 is a prime.

It is a super-2 number, since 2×20519927981² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20519927983) 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, 1463141 + ... + 1477098.

It is an arithmetic number, because the mean of its divisors is an integer number (2934359520).

Almost surely, 2^20519927981 is an apocalyptic number.

It is an amenable number.

20519927981 is a deficient number, since it is larger than the sum of its proper divisors (2954948179).

20519927981 is an equidigital number, since it uses as much as digits as its factorization.

20519927981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2941243.

The product of its (nonzero) digits is 816480, while the sum is 53.

The spelling of 20519927981 in words is "twenty billion, five hundred nineteen million, nine hundred twenty-seven thousand, nine hundred eighty-one".