61566553 has 2 divisors, whose sum is σ = 61566554. Its totient is φ = 61566552.

The previous prime is 61566541. The next prime is 61566563. The reversal of 61566553 is 35566516.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 34609689 + 26956864 = 5883^2 + 5192^2 .

It is a cyclic number.

It is not a de Polignac number, because 61566553 - 2²⁵ = 28012121 is a prime.

It is not a weakly prime, because it can be changed into another prime (61566523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30783276 + 30783277.

It is an arithmetic number, because the mean of its divisors is an integer number (30783277).

Almost surely, 2^61566553 is an apocalyptic number.

It is an amenable number.

61566553 is a deficient number, since it is larger than the sum of its proper divisors (1).

61566553 is an equidigital number, since it uses as much as digits as its factorization.

61566553 is an evil number, because the sum of its binary digits is even.

The product of its digits is 81000, while the sum is 37.

The square root of 61566553 is about 7846.4356876228. The cubic root of 61566553 is about 394.8646719025.

Subtracting from 61566553 its sum of digits (37), we obtain a palindrome (61566516).

The spelling of 61566553 in words is "sixty-one million, five hundred sixty-six thousand, five hundred fifty-three".