4681981 has 2 divisors, whose sum is σ = 4681982. Its totient is φ = 4681980.

The previous prime is 4681973. The next prime is 4681991. The reversal of 4681981 is 1891864.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2859481 + 1822500 = 1691^2 + 1350^2 .

It is a cyclic number.

It is not a de Polignac number, because 4681981 - 2³ = 4681973 is a prime.

It is a super-2 number, since 2×4681981² = 43841892168722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 4681981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (4681921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2340990 + 2340991.

It is an arithmetic number, because the mean of its divisors is an integer number (2340991).

Almost surely, 2^4681981 is an apocalyptic number.

4681981 is the 1369-th centered pentagonal number.

It is an amenable number.

4681981 is a deficient number, since it is larger than the sum of its proper divisors (1).

4681981 is an equidigital number, since it uses as much as digits as its factorization.

4681981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13824, while the sum is 37.

The square root of 4681981 is about 2163.7885756238. The cubic root of 4681981 is about 167.2925299402.

The spelling of 4681981 in words is "four million, six hundred eighty-one thousand, nine hundred eighty-one".