349470721 has 4 divisors (see below), whose sum is σ = 350305200. Its totient is φ = 348636244.

The previous prime is 349470707. The next prime is 349470749. The reversal of 349470721 is 127074943.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 127074943 = 769 ⋅165247.

It is a cyclic number.

It is not a de Polignac number, because 349470721 - 2⁵ = 349470689 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (349470701) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 416611 + ... + 417448.

It is an arithmetic number, because the mean of its divisors is an integer number (87576300).

It is a Proth number, since it is equal to 10665 ⋅ 2¹⁵ + 1 and 10665 < 2¹⁵.

Almost surely, 2^349470721 is an apocalyptic number.

It is an amenable number.

349470721 is a deficient number, since it is larger than the sum of its proper divisors (834479).

349470721 is an equidigital number, since it uses as much as digits as its factorization.

349470721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 834478.

The product of its (nonzero) digits is 42336, while the sum is 37.

The square root of 349470721 is about 18694.1360057105. The cubic root of 349470721 is about 704.3744571112.

The spelling of 349470721 in words is "three hundred forty-nine million, four hundred seventy thousand, seven hundred twenty-one".