83528721 has 12 divisors (see below), whose sum is σ = 123913972. Its totient is φ = 54180576.

The previous prime is 83528713. The next prime is 83528741. The reversal of 83528721 is 12782538.

It can be written as a sum of positive squares in 2 ways, for example, as 70308225 + 13220496 = 8385^2 + 3636^2 .

It is not a de Polignac number, because 83528721 - 2³ = 83528713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (83528741) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 125086 + ... + 125751.

Almost surely, 2^83528721 is an apocalyptic number.

It is an amenable number.

83528721 is a deficient number, since it is larger than the sum of its proper divisors (40385251).

83528721 is a wasteful number, since it uses less digits than its factorization.

83528721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 250880 (or 250877 counting only the distinct ones).

The product of its digits is 26880, while the sum is 36.

The square root of 83528721 is about 9139.4048493324. The cubic root of 83528721 is about 437.1313396116.

The spelling of 83528721 in words is "eighty-three million, five hundred twenty-eight thousand, seven hundred twenty-one".