20966981 has 8 divisors (see below), whose sum is σ = 24355584. Its totient is φ = 17676720.

The previous prime is 20966969. The next prime is 20966983. The reversal of 20966981 is 18966902.

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 20966981 - 2¹⁸ = 20704837 is a prime.

It is a super-2 number, since 2×20966981² = 879228584508722, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20966983) 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, 24125 + ... + 24978.

It is an arithmetic number, because the mean of its divisors is an integer number (3044448).

Almost surely, 2^20966981 is an apocalyptic number.

It is an amenable number.

20966981 is a deficient number, since it is larger than the sum of its proper divisors (3388603).

20966981 is an equidigital number, since it uses as much as digits as its factorization.

20966981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49171.

The product of its (nonzero) digits is 46656, while the sum is 41.

The square root of 20966981 is about 4578.9716094337. The cubic root of 20966981 is about 275.7477435047.

The spelling of 20966981 in words is "twenty million, nine hundred sixty-six thousand, nine hundred eighty-one".