749739721 has 2 divisors, whose sum is σ = 749739722. Its totient is φ = 749739720.

The previous prime is 749739719. The next prime is 749739737. The reversal of 749739721 is 127937947.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 712089225 + 37650496 = 26685^2 + 6136^2 .

It is an emirp because it is prime and its reverse (127937947) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 749739721 - 2¹ = 749739719 is a prime.

Together with 749739719, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (749739121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 374869860 + 374869861.

It is an arithmetic number, because the mean of its divisors is an integer number (374869861).

Almost surely, 2^749739721 is an apocalyptic number.

It is an amenable number.

749739721 is a deficient number, since it is larger than the sum of its proper divisors (1).

749739721 is an equidigital number, since it uses as much as digits as its factorization.

749739721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 666792, while the sum is 49.

The square root of 749739721 is about 27381.3754402514. The cubic root of 749739721 is about 908.4551824043.

The spelling of 749739721 in words is "seven hundred forty-nine million, seven hundred thirty-nine thousand, seven hundred twenty-one".