61571591 has 2 divisors, whose sum is σ = 61571592. Its totient is φ = 61571590.

The previous prime is 61571567. The next prime is 61571617. The reversal of 61571591 is 19517516.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 61571591 - 2⁶ = 61571527 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61571561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30785795 + 30785796.

It is an arithmetic number, because the mean of its divisors is an integer number (30785796).

Almost surely, 2^61571591 is an apocalyptic number.

61571591 is a deficient number, since it is larger than the sum of its proper divisors (1).

61571591 is an equidigital number, since it uses as much as digits as its factorization.

61571591 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9450, while the sum is 35.

The square root of 61571591 is about 7846.7567185430. The cubic root of 61571591 is about 394.8754422199.

The spelling of 61571591 in words is "sixty-one million, five hundred seventy-one thousand, five hundred ninety-one".