82436721 has 4 divisors (see below), whose sum is σ = 109915632. Its totient is φ = 54957812.

The previous prime is 82436707. The next prime is 82436741. The reversal of 82436721 is 12763428.

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.

It is a cyclic number.

It is not a de Polignac number, because 82436721 - 2¹⁸ = 82174577 is a prime.

It is not an unprimeable number, because it can be changed into a prime (82436741) 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, 13739451 + ... + 13739456.

It is an arithmetic number, because the mean of its divisors is an integer number (27478908).

Almost surely, 2^82436721 is an apocalyptic number.

It is an amenable number.

82436721 is a deficient number, since it is larger than the sum of its proper divisors (27478911).

82436721 is a wasteful number, since it uses less digits than its factorization.

82436721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27478910.

The product of its digits is 16128, while the sum is 33.

The square root of 82436721 is about 9079.4669997748. The cubic root of 82436721 is about 435.2180542387.

The spelling of 82436721 in words is "eighty-two million, four hundred thirty-six thousand, seven hundred twenty-one".