61091791 has 2 divisors, whose sum is σ = 61091792. Its totient is φ = 61091790.

The previous prime is 61091747. The next prime is 61091809. The reversal of 61091791 is 19719016.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 61091791 - 2¹⁵ = 61059023 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61091711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30545895 + 30545896.

It is an arithmetic number, because the mean of its divisors is an integer number (30545896).

Almost surely, 2^61091791 is an apocalyptic number.

61091791 is a deficient number, since it is larger than the sum of its proper divisors (1).

61091791 is an equidigital number, since it uses as much as digits as its factorization.

61091791 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3402, while the sum is 34.

The square root of 61091791 is about 7816.1237835643. The cubic root of 61091791 is about 393.8470701803.

The spelling of 61091791 in words is "sixty-one million, ninety-one thousand, seven hundred ninety-one".