20981221995 has 8 divisors (see below), whose sum is σ = 33569955216. Its totient is φ = 11189985056.

The previous prime is 20981221991. The next prime is 20981222011. The reversal of 20981221995 is 59912218902.

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

It is a cyclic number.

It is not a de Polignac number, because 20981221995 - 2² = 20981221991 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20981221991) 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, 699374052 + ... + 699374081.

It is an arithmetic number, because the mean of its divisors is an integer number (4196244402).

Almost surely, 2^20981221995 is an apocalyptic number.

20981221995 is a deficient number, since it is larger than the sum of its proper divisors (12588733221).

20981221995 is a wasteful number, since it uses less digits than its factorization.

20981221995 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1398748141.

The product of its (nonzero) digits is 233280, while the sum is 48.

The spelling of 20981221995 in words is "twenty billion, nine hundred eighty-one million, two hundred twenty-one thousand, nine hundred ninety-five".