61389989 has 2 divisors, whose sum is σ = 61389990. Its totient is φ = 61389988.

The previous prime is 61389971. The next prime is 61390001. The reversal of 61389989 is 98998316.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 34692100 + 26697889 = 5890^2 + 5167^2 .

It is a cyclic number.

It is not a de Polignac number, because 61389989 - 2⁸ = 61389733 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 61389989.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61389929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30694994 + 30694995.

It is an arithmetic number, because the mean of its divisors is an integer number (30694995).

Almost surely, 2^61389989 is an apocalyptic number.

It is an amenable number.

61389989 is a deficient number, since it is larger than the sum of its proper divisors (1).

61389989 is an equidigital number, since it uses as much as digits as its factorization.

61389989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 839808, while the sum is 53.

The square root of 61389989 is about 7835.1763860171. The cubic root of 61389989 is about 394.4868388269.

The spelling of 61389989 in words is "sixty-one million, three hundred eighty-nine thousand, nine hundred eighty-nine".