53561591 has 2 divisors, whose sum is σ = 53561592. Its totient is φ = 53561590.

The previous prime is 53561587. The next prime is 53561593. The reversal of 53561591 is 19516535.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 53561591 - 2² = 53561587 is a prime.

It is a Sophie Germain prime.

Together with 53561593, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (53561593) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 26780795 + 26780796.

It is an arithmetic number, because the mean of its divisors is an integer number (26780796).

Almost surely, 2^53561591 is an apocalyptic number.

53561591 is a deficient number, since it is larger than the sum of its proper divisors (1).

53561591 is an equidigital number, since it uses as much as digits as its factorization.

53561591 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20250, while the sum is 35.

The square root of 53561591 is about 7318.5784821917. The cubic root of 53561591 is about 376.9506440041.

It can be divided in two parts, 535 and 61591, that added together give a palindrome (62126).

The spelling of 53561591 in words is "fifty-three million, five hundred sixty-one thousand, five hundred ninety-one".