61750721 has 2 divisors, whose sum is σ = 61750722. Its totient is φ = 61750720.

The previous prime is 61750697. The next prime is 61750723. The reversal of 61750721 is 12705716.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 42706225 + 19044496 = 6535^2 + 4364^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61750721 is a prime.

Together with 61750723, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (61750723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30875360 + 30875361.

It is an arithmetic number, because the mean of its divisors is an integer number (30875361).

Almost surely, 2^61750721 is an apocalyptic number.

It is an amenable number.

61750721 is a deficient number, since it is larger than the sum of its proper divisors (1).

61750721 is an equidigital number, since it uses as much as digits as its factorization.

61750721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2940, while the sum is 29.

The square root of 61750721 is about 7858.1626987484. The cubic root of 61750721 is about 395.2580080107.

The spelling of 61750721 in words is "sixty-one million, seven hundred fifty thousand, seven hundred twenty-one".