61443989 has 2 divisors, whose sum is σ = 61443990. Its totient is φ = 61443988.

The previous prime is 61443983. The next prime is 61444007. The reversal of 61443989 is 98934416.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 54982225 + 6461764 = 7415^2 + 2542^2 .

It is a cyclic number.

It is not a de Polignac number, because 61443989 - 2⁴ = 61443973 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61443983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30721994 + 30721995.

It is an arithmetic number, because the mean of its divisors is an integer number (30721995).

Almost surely, 2^61443989 is an apocalyptic number.

It is an amenable number.

61443989 is a deficient number, since it is larger than the sum of its proper divisors (1).

61443989 is an equidigital number, since it uses as much as digits as its factorization.

61443989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 186624, while the sum is 44.

The square root of 61443989 is about 7838.6216262810. The cubic root of 61443989 is about 394.6024713955.

The spelling of 61443989 in words is "sixty-one million, four hundred forty-three thousand, nine hundred eighty-nine".