361021981 has 2 divisors, whose sum is σ = 361021982. Its totient is φ = 361021980.

The previous prime is 361021967. The next prime is 361022033. The reversal of 361021981 is 189120163.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 351225081 + 9796900 = 18741^2 + 3130^2 .

It is a cyclic number.

It is not a de Polignac number, because 361021981 - 2⁷ = 361021853 is a prime.

It is a super-2 number, since 2×361021981² = 260673741530328722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (361021951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 180510990 + 180510991.

It is an arithmetic number, because the mean of its divisors is an integer number (180510991).

Almost surely, 2^361021981 is an apocalyptic number.

It is an amenable number.

361021981 is a deficient number, since it is larger than the sum of its proper divisors (1).

361021981 is an equidigital number, since it uses as much as digits as its factorization.

361021981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2592, while the sum is 31.

The square root of 361021981 is about 19000.5784385634. The cubic root of 361021981 is about 712.0511873785.

It can be divided in two parts, 36102 and 1981, that added together give a palindrome (38083).

The spelling of 361021981 in words is "three hundred sixty-one million, twenty-one thousand, nine hundred eighty-one".