83521261 has 4 divisors (see below), whose sum is σ = 84890524. Its totient is φ = 82152000.

The previous prime is 83521253. The next prime is 83521267. The reversal of 83521261 is 16212538.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 21206025 + 62315236 = 4605^2 + 7894^2 .

It is a cyclic number.

It is not a de Polignac number, because 83521261 - 2³ = 83521253 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (83521267) 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, 684540 + ... + 684661.

It is an arithmetic number, because the mean of its divisors is an integer number (21222631).

Almost surely, 2^83521261 is an apocalyptic number.

It is an amenable number.

83521261 is a deficient number, since it is larger than the sum of its proper divisors (1369263).

83521261 is a wasteful number, since it uses less digits than its factorization.

83521261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1369262.

The product of its digits is 2880, while the sum is 28.

The square root of 83521261 is about 9138.9967173645. The cubic root of 83521261 is about 437.1183257371.

Adding to 83521261 its reverse (16212538), we get a palindrome (99733799).

The spelling of 83521261 in words is "eighty-three million, five hundred twenty-one thousand, two hundred sixty-one".