349428721 has 2 divisors, whose sum is σ = 349428722. Its totient is φ = 349428720.

The previous prime is 349428697. The next prime is 349428731. The reversal of 349428721 is 127824943.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 347412321 + 2016400 = 18639^2 + 1420^2 .

It is an emirp because it is prime and its reverse (127824943) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 349428721 - 2¹¹ = 349426673 is a prime.

It is not a weakly prime, because it can be changed into another prime (349428731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 174714360 + 174714361.

It is an arithmetic number, because the mean of its divisors is an integer number (174714361).

Almost surely, 2^349428721 is an apocalyptic number.

It is an amenable number.

349428721 is a deficient number, since it is larger than the sum of its proper divisors (1).

349428721 is an equidigital number, since it uses as much as digits as its factorization.

349428721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 96768, while the sum is 40.

The square root of 349428721 is about 18693.0126250425. The cubic root of 349428721 is about 704.3462383309.

The spelling of 349428721 in words is "three hundred forty-nine million, four hundred twenty-eight thousand, seven hundred twenty-one".