84745021 has 4 divisors (see below), whose sum is σ = 84774844. Its totient is φ = 84715200.

The previous prime is 84745019. The next prime is 84745027. The reversal of 84745021 is 12054748.

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 5784025 + 78960996 = 2405^2 + 8886^2 .

It is a cyclic number.

It is not a de Polignac number, because 84745021 - 2¹ = 84745019 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 (84745027) 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, 10140 + ... + 16501.

It is an arithmetic number, because the mean of its divisors is an integer number (21193711).

Almost surely, 2^84745021 is an apocalyptic number.

It is an amenable number.

84745021 is a deficient number, since it is larger than the sum of its proper divisors (29823).

84745021 is a wasteful number, since it uses less digits than its factorization.

84745021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29822.

The product of its (nonzero) digits is 8960, while the sum is 31.

The square root of 84745021 is about 9205.7058936292. The cubic root of 84745021 is about 439.2428801131.

Adding to 84745021 its reverse (12054748), we get a palindrome (96799769).

The spelling of 84745021 in words is "eighty-four million, seven hundred forty-five thousand, twenty-one".