61566539 has 2 divisors, whose sum is σ = 61566540. Its totient is φ = 61566538.

The previous prime is 61566523. The next prime is 61566541. The reversal of 61566539 is 93566516.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 61566539 - 2⁴ = 61566523 is a prime.

It is a Sophie Germain prime.

Together with 61566541, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 61566496 and 61566505.

It is not a weakly prime, because it can be changed into another prime (61566599) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30783269 + 30783270.

It is an arithmetic number, because the mean of its divisors is an integer number (30783270).

Almost surely, 2^61566539 is an apocalyptic number.

61566539 is a deficient number, since it is larger than the sum of its proper divisors (1).

61566539 is an equidigital number, since it uses as much as digits as its factorization.

61566539 is an evil number, because the sum of its binary digits is even.

The product of its digits is 145800, while the sum is 41.

The square root of 61566539 is about 7846.4347954979. The cubic root of 61566539 is about 394.8646419722.

The spelling of 61566539 in words is "sixty-one million, five hundred sixty-six thousand, five hundred thirty-nine".