61810139 has 2 divisors, whose sum is σ = 61810140. Its totient is φ = 61810138.

The previous prime is 61810127. The next prime is 61810157. The reversal of 61810139 is 93101816.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61810139 is a prime.

It is not a weakly prime, because it can be changed into another prime (61812139) 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, 30905069 + 30905070.

It is an arithmetic number, because the mean of its divisors is an integer number (30905070).

Almost surely, 2^61810139 is an apocalyptic number.

61810139 is a deficient number, since it is larger than the sum of its proper divisors (1).

61810139 is an equidigital number, since it uses as much as digits as its factorization.

61810139 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 29.

The square root of 61810139 is about 7861.9424444599. The cubic root of 61810139 is about 395.3847428958.

The spelling of 61810139 in words is "sixty-one million, eight hundred ten thousand, one hundred thirty-nine".