61921289 has 2 divisors, whose sum is σ = 61921290. Its totient is φ = 61921288.

The previous prime is 61921261. The next prime is 61921297. The reversal of 61921289 is 98212916.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 44448889 + 17472400 = 6667^2 + 4180^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61921289 is a prime.

It is not a weakly prime, because it can be changed into another prime (61921789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30960644 + 30960645.

It is an arithmetic number, because the mean of its divisors is an integer number (30960645).

Almost surely, 2^61921289 is an apocalyptic number.

It is an amenable number.

61921289 is a deficient number, since it is larger than the sum of its proper divisors (1).

61921289 is an equidigital number, since it uses as much as digits as its factorization.

61921289 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15552, while the sum is 38.

The square root of 61921289 is about 7869.0081331766. The cubic root of 61921289 is about 395.6216010047.

The spelling of 61921289 in words is "sixty-one million, nine hundred twenty-one thousand, two hundred eighty-nine".