61611521 has 2 divisors, whose sum is σ = 61611522. Its totient is φ = 61611520.

The previous prime is 61611499. The next prime is 61611533. The reversal of 61611521 is 12511616.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 37650496 + 23961025 = 6136^2 + 4895^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61611521 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (61611541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30805760 + 30805761.

It is an arithmetic number, because the mean of its divisors is an integer number (30805761).

Almost surely, 2^61611521 is an apocalyptic number.

It is an amenable number.

61611521 is a deficient number, since it is larger than the sum of its proper divisors (1).

61611521 is an equidigital number, since it uses as much as digits as its factorization.

61611521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 360, while the sum is 23.

The square root of 61611521 is about 7849.3006694864. The cubic root of 61611521 is about 394.9607844420.

The spelling of 61611521 in words is "sixty-one million, six hundred eleven thousand, five hundred twenty-one".