749071721 has 2 divisors, whose sum is σ = 749071722. Its totient is φ = 749071720.

The previous prime is 749071709. The next prime is 749071727. The reversal of 749071721 is 127170947.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 736362496 + 12709225 = 27136^2 + 3565^2 .

It is an emirp because it is prime and its reverse (127170947) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 749071721 - 2¹⁴ = 749055337 is a prime.

It is a super-2 number, since 2×749071721² = 1122216886403803682, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (749071727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 374535860 + 374535861.

It is an arithmetic number, because the mean of its divisors is an integer number (374535861).

Almost surely, 2^749071721 is an apocalyptic number.

It is an amenable number.

749071721 is a deficient number, since it is larger than the sum of its proper divisors (1).

749071721 is an equidigital number, since it uses as much as digits as its factorization.

749071721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24696, while the sum is 38.

The square root of 749071721 is about 27369.1746495944. The cubic root of 749071721 is about 908.1852983529.

The spelling of 749071721 in words is "seven hundred forty-nine million, seventy-one thousand, seven hundred twenty-one".