19964981 has 2 divisors, whose sum is σ = 19964982. Its totient is φ = 19964980.

The previous prime is 19964969. The next prime is 19964993. The reversal of 19964981 is 18946991.

It is a balanced prime because it is at equal distance from previous prime (19964969) and next prime (19964993).

It can be written as a sum of positive squares in only one way, i.e., 13256881 + 6708100 = 3641^2 + 2590^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19964981 is a prime.

It is a super-2 number, since 2×19964981² = 797200932660722, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19964921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9982490 + 9982491.

It is an arithmetic number, because the mean of its divisors is an integer number (9982491).

Almost surely, 2^19964981 is an apocalyptic number.

It is an amenable number.

19964981 is a deficient number, since it is larger than the sum of its proper divisors (1).

19964981 is an equidigital number, since it uses as much as digits as its factorization.

19964981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 139968, while the sum is 47.

The square root of 19964981 is about 4468.2189964235. The cubic root of 19964981 is about 271.2832421193.

The spelling of 19964981 in words is "nineteen million, nine hundred sixty-four thousand, nine hundred eighty-one".