21982798991 has 8 divisors (see below), whose sum is σ = 23295436704. Its totient is φ = 20672331520.

The previous prime is 21982798939. The next prime is 21982798993. The reversal of 21982798991 is 19989728912.

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 21982798991 - 2⁶ = 21982798927 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21982798993) 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, 521675 + ... + 562236.

It is an arithmetic number, because the mean of its divisors is an integer number (2911929588).

Almost surely, 2^21982798991 is an apocalyptic number.

21982798991 is a deficient number, since it is larger than the sum of its proper divisors (1312637713).

21982798991 is a wasteful number, since it uses less digits than its factorization.

21982798991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1085121.

The product of its digits is 11757312, while the sum is 65.

The spelling of 21982798991 in words is "twenty-one billion, nine hundred eighty-two million, seven hundred ninety-eight thousand, nine hundred ninety-one".