21196580981 has 8 divisors (see below), whose sum is σ = 21366062520. Its totient is φ = 21027768768.

The previous prime is 21196580969. The next prime is 21196580983. The reversal of 21196580981 is 18908569112.

It can be written as a sum of positive squares in 4 ways, for example, as 2816000356 + 18380580625 = 53066^2 + 135575^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21196580981 is a prime.

It is a super-2 number, since 2×21196580981² (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 (21196580983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 103646 + ... + 230511.

It is an arithmetic number, because the mean of its divisors is an integer number (2670757815).

Almost surely, 2^21196580981 is an apocalyptic number.

It is an amenable number.

21196580981 is a deficient number, since it is larger than the sum of its proper divisors (169481539).

21196580981 is a wasteful number, since it uses less digits than its factorization.

21196580981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 334663.

The product of its (nonzero) digits is 311040, while the sum is 50.

The spelling of 21196580981 in words is "twenty-one billion, one hundred ninety-six million, five hundred eighty thousand, nine hundred eighty-one".