61423721 has 2 divisors, whose sum is σ = 61423722. Its totient is φ = 61423720.

The previous prime is 61423697. The next prime is 61423727. The reversal of 61423721 is 12732416.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 58308496 + 3115225 = 7636^2 + 1765^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61423721 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 (61423727) by changing a digit.

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

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30711860 + 30711861.

It is an arithmetic number, because the mean of its divisors is an integer number (30711861).

Almost surely, 2^61423721 is an apocalyptic number.

It is an amenable number.

61423721 is a deficient number, since it is larger than the sum of its proper divisors (1).

61423721 is an equidigital number, since it uses as much as digits as its factorization.

61423721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2016, while the sum is 26.

The square root of 61423721 is about 7837.3286903128. The cubic root of 61423721 is about 394.5590785833.

The spelling of 61423721 in words is "sixty-one million, four hundred twenty-three thousand, seven hundred twenty-one".