3507721 has 4 divisors (see below), whose sum is σ = 4008832. Its totient is φ = 3006612.

The previous prime is 3507719. The next prime is 3507731. The reversal of 3507721 is 1277053.

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: 1277053 = 431 ⋅2963.

It is not a de Polignac number, because 3507721 - 2¹ = 3507719 is a prime.

It is a super-2 number, since 2×3507721² = 24608213227682, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3507731) 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, 250545 + ... + 250558.

It is an arithmetic number, because the mean of its divisors is an integer number (1002208).

Almost surely, 2^3507721 is an apocalyptic number.

It is an amenable number.

3507721 is a deficient number, since it is larger than the sum of its proper divisors (501111).

3507721 is an equidigital number, since it uses as much as digits as its factorization.

3507721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 501110.

The product of its (nonzero) digits is 1470, while the sum is 25.

The square root of 3507721 is about 1872.8910806558. The cubic root of 3507721 is about 151.9410118523.

The spelling of 3507721 in words is "three million, five hundred seven thousand, seven hundred twenty-one".