61721603 has 2 divisors, whose sum is σ = 61721604. Its totient is φ = 61721602.

The previous prime is 61721563. The next prime is 61721623. The reversal of 61721603 is 30612716.

61721603 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 61721603 - 2¹⁰ = 61720579 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (61721623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30860801 + 30860802.

It is an arithmetic number, because the mean of its divisors is an integer number (30860802).

Almost surely, 2^61721603 is an apocalyptic number.

61721603 is a deficient number, since it is larger than the sum of its proper divisors (1).

61721603 is an equidigital number, since it uses as much as digits as its factorization.

61721603 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1512, while the sum is 26.

The square root of 61721603 is about 7856.3097571315. The cubic root of 61721603 is about 395.1958714506.

The spelling of 61721603 in words is "sixty-one million, seven hundred twenty-one thousand, six hundred three".