3505721 has 4 divisors (see below), whose sum is σ = 3565200. Its totient is φ = 3446244.

The previous prime is 3505699. The next prime is 3505727. The reversal of 3505721 is 1275053.

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: 1275053 = 13 ⋅98081.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3505721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3505727) 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, 29651 + ... + 29768.

It is an arithmetic number, because the mean of its divisors is an integer number (891300).

Almost surely, 2^3505721 is an apocalyptic number.

It is an amenable number.

3505721 is a deficient number, since it is larger than the sum of its proper divisors (59479).

3505721 is an equidigital number, since it uses as much as digits as its factorization.

3505721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59478.

The product of its (nonzero) digits is 1050, while the sum is 23.

The square root of 3505721 is about 1872.3570706465. The cubic root of 3505721 is about 151.9121289207.

The spelling of 3505721 in words is "three million, five hundred five thousand, seven hundred twenty-one".