61145531761 has 2 divisors, whose sum is σ = 61145531762. Its totient is φ = 61145531760.

The previous prime is 61145531731. The next prime is 61145531801. The reversal of 61145531761 is 16713554116.

It is an a-pointer prime, because the next prime (61145531801) can be obtained adding 61145531761 to its sum of digits (40).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 59653177600 + 1492354161 = 244240^2 + 38631^2 .

It is a cyclic number.

It is not a de Polignac number, because 61145531761 - 2³³ = 52555597169 is a prime.

It is a super-2 number, since 2×61145531761² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (61145531731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30572765880 + 30572765881.

It is an arithmetic number, because the mean of its divisors is an integer number (30572765881).

Almost surely, 2^61145531761 is an apocalyptic number.

It is an amenable number.

61145531761 is a deficient number, since it is larger than the sum of its proper divisors (1).

61145531761 is an equidigital number, since it uses as much as digits as its factorization.

61145531761 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 75600, while the sum is 40.

The spelling of 61145531761 in words is "sixty-one billion, one hundred forty-five million, five hundred thirty-one thousand, seven hundred sixty-one".