61157581 has 2 divisors, whose sum is σ = 61157582. Its totient is φ = 61157580.

The previous prime is 61157573. The next prime is 61157587. The reversal of 61157581 is 18575116.

61157581 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59444100 + 1713481 = 7710^2 + 1309^2 .

It is a cyclic number.

It is not a de Polignac number, because 61157581 - 2³ = 61157573 is a prime.

It is a super-2 number, since 2×61157581² = 7480499427543122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61157587) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30578790 + 30578791.

It is an arithmetic number, because the mean of its divisors is an integer number (30578791).

Almost surely, 2^61157581 is an apocalyptic number.

It is an amenable number.

61157581 is a deficient number, since it is larger than the sum of its proper divisors (1).

61157581 is an equidigital number, since it uses as much as digits as its factorization.

61157581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8400, while the sum is 34.

The square root of 61157581 is about 7820.3312589685. The cubic root of 61157581 is about 393.9883979680.

The spelling of 61157581 in words is "sixty-one million, one hundred fifty-seven thousand, five hundred eighty-one".