61033981 has 2 divisors, whose sum is σ = 61033982. Its totient is φ = 61033980.

The previous prime is 61033939. The next prime is 61033993. The reversal of 61033981 is 18933016.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 54096025 + 6937956 = 7355^2 + 2634^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61033981 is a prime.

It is a super-2 number, since 2×61033981² = 7450293673416722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61033901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30516990 + 30516991.

It is an arithmetic number, because the mean of its divisors is an integer number (30516991).

Almost surely, 2^61033981 is an apocalyptic number.

It is an amenable number.

61033981 is a deficient number, since it is larger than the sum of its proper divisors (1).

61033981 is an equidigital number, since it uses as much as digits as its factorization.

61033981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3888, while the sum is 31.

The square root of 61033981 is about 7812.4247836379. The cubic root of 61033981 is about 393.7228009767.

Adding to 61033981 its reverse (18933016), we get a palindrome (79966997).

The spelling of 61033981 in words is "sixty-one million, thirty-three thousand, nine hundred eighty-one".