61890344137 has 2 divisors, whose sum is σ = 61890344138. Its totient is φ = 61890344136.

The previous prime is 61890344123. The next prime is 61890344161. The reversal of 61890344137 is 73144309816.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 44333829136 + 17556515001 = 210556^2 + 132501^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61890344137 is a prime.

It is not a weakly prime, because it can be changed into another prime (61890344107) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30945172068 + 30945172069.

It is an arithmetic number, because the mean of its divisors is an integer number (30945172069).

Almost surely, 2^61890344137 is an apocalyptic number.

It is an amenable number.

61890344137 is a deficient number, since it is larger than the sum of its proper divisors (1).

61890344137 is an equidigital number, since it uses as much as digits as its factorization.

61890344137 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 435456, while the sum is 46.

The spelling of 61890344137 in words is "sixty-one billion, eight hundred ninety million, three hundred forty-four thousand, one hundred thirty-seven".