3531879721 has 4 divisors (see below), whose sum is σ = 3543934212. Its totient is φ = 3519825232.

The previous prime is 3531879679. The next prime is 3531879731. The reversal of 3531879721 is 1279781353.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1279781353 = 751 ⋅1704103.

It can be written as a sum of positive squares in 2 ways, for example, as 1694557225 + 1837322496 = 41165^2 + 42864^2 .

It is a cyclic number.

It is not a de Polignac number, because 3531879721 - 2²¹ = 3529782569 is a prime.

It is a super-2 number, since 2×3531879721² = 24948348727222075682, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3531879731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6026806 + ... + 6027391.

It is an arithmetic number, because the mean of its divisors is an integer number (885983553).

Almost surely, 2^3531879721 is an apocalyptic number.

It is an amenable number.

3531879721 is a deficient number, since it is larger than the sum of its proper divisors (12054491).

3531879721 is a wasteful number, since it uses less digits than its factorization.

3531879721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12054490.

The product of its digits is 317520, while the sum is 46.

The square root of 3531879721 is about 59429.6198961427. The cubic root of 3531879721 is about 1522.8903511688.

The spelling of 3531879721 in words is "three billion, five hundred thirty-one million, eight hundred seventy-nine thousand, seven hundred twenty-one".