4249321981 has 2 divisors, whose sum is σ = 4249321982. Its totient is φ = 4249321980.

The previous prime is 4249321949. The next prime is 4249321987. The reversal of 4249321981 is 1891239424.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3851319481 + 398002500 = 62059^2 + 19950^2 .

It is a cyclic number.

It is not a de Polignac number, because 4249321981 - 2⁵ = 4249321949 is a prime.

It is a super-2 number, since 2×4249321981² = 36113474596419528722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (4249321987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2124660990 + 2124660991.

It is an arithmetic number, because the mean of its divisors is an integer number (2124660991).

Almost surely, 2^4249321981 is an apocalyptic number.

It is an amenable number.

4249321981 is a deficient number, since it is larger than the sum of its proper divisors (1).

4249321981 is an equidigital number, since it uses as much as digits as its factorization.

4249321981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 124416, while the sum is 43.

The square root of 4249321981 is about 65186.8236762614. The cubic root of 4249321981 is about 1619.7197580830.

The spelling of 4249321981 in words is "four billion, two hundred forty-nine million, three hundred twenty-one thousand, nine hundred eighty-one".