84231021 has 16 divisors (see below), whose sum is σ = 128767104. Its totient is φ = 47976384.

The previous prime is 84231019. The next prime is 84231029. The reversal of 84231021 is 12013248.

It is not a de Polignac number, because 84231021 - 2¹ = 84231019 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (84231029) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 331 + ... + 12983.

It is an arithmetic number, because the mean of its divisors is an integer number (8047944).

Almost surely, 2^84231021 is an apocalyptic number.

It is an amenable number.

84231021 is a deficient number, since it is larger than the sum of its proper divisors (44536083).

84231021 is a wasteful number, since it uses less digits than its factorization.

84231021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12980.

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 84231021 is about 9177.7459651049. The cubic root of 84231021 is about 438.3530388991.

Adding to 84231021 its reverse (12013248), we get a palindrome (96244269).

The spelling of 84231021 in words is "eighty-four million, two hundred thirty-one thousand, twenty-one".