61245546581 has 2 divisors, whose sum is σ = 61245546582. Its totient is φ = 61245546580.

The previous prime is 61245546547. The next prime is 61245546623. The reversal of 61245546581 is 18564554216.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 48551919025 + 12693627556 = 220345^2 + 112666^2 .

It is a cyclic number.

It is not a de Polignac number, because 61245546581 - 2²⁶ = 61178437717 is a prime.

It is a super-2 number, since 2×61245546581² (a number of 22 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61245549581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30622773290 + 30622773291.

It is an arithmetic number, because the mean of its divisors is an integer number (30622773291).

Almost surely, 2^61245546581 is an apocalyptic number.

It is an amenable number.

61245546581 is a deficient number, since it is larger than the sum of its proper divisors (1).

61245546581 is an equidigital number, since it uses as much as digits as its factorization.

61245546581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1152000, while the sum is 47.

The spelling of 61245546581 in words is "sixty-one billion, two hundred forty-five million, five hundred forty-six thousand, five hundred eighty-one".