84910021 has 4 divisors (see below), whose sum is σ = 97040032. Its totient is φ = 72780012.

The previous prime is 84910013. The next prime is 84910039. The reversal of 84910021 is 12001948.

It is a happy number.

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 84910021 - 2³ = 84910013 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 (84910621) 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, 6064995 + ... + 6065008.

It is an arithmetic number, because the mean of its divisors is an integer number (24260008).

Almost surely, 2^84910021 is an apocalyptic number.

It is an amenable number.

84910021 is a deficient number, since it is larger than the sum of its proper divisors (12130011).

84910021 is a wasteful number, since it uses less digits than its factorization.

84910021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12130010.

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 84910021 is about 9214.6633687835. The cubic root of 84910021 is about 439.5277664244.

Subtracting from 84910021 its sum of digits (25), we obtain a triangular number (84909996 = T₁₃₀₃₁).

Adding to 84910021 its reverse (12001948), we get a palindrome (96911969).

The spelling of 84910021 in words is "eighty-four million, nine hundred ten thousand, twenty-one".