61047821 has 2 divisors, whose sum is σ = 61047822. Its totient is φ = 61047820.

The previous prime is 61047797. The next prime is 61047829. The reversal of 61047821 is 12874016.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 61011721 + 36100 = 7811^2 + 190^2 .

It is a cyclic number.

It is not a de Polignac number, because 61047821 - 2¹⁴ = 61031437 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61047829) 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, 30523910 + 30523911.

It is an arithmetic number, because the mean of its divisors is an integer number (30523911).

Almost surely, 2^61047821 is an apocalyptic number.

It is an amenable number.

61047821 is a deficient number, since it is larger than the sum of its proper divisors (1).

61047821 is an equidigital number, since it uses as much as digits as its factorization.

61047821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2688, while the sum is 29.

The square root of 61047821 is about 7813.3105019575. The cubic root of 61047821 is about 393.7525587807.

The spelling of 61047821 in words is "sixty-one million, forty-seven thousand, eight hundred twenty-one".