84021389 has 4 divisors (see below), whose sum is σ = 84051900. Its totient is φ = 83990880.

The previous prime is 84021373. The next prime is 84021403. The reversal of 84021389 is 98312048.

It is a happy number.

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 72965764 + 11055625 = 8542^2 + 3325^2 .

It is a cyclic number.

It is not a de Polignac number, because 84021389 - 2⁴ = 84021373 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 (84021359) 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, 10664 + ... + 16785.

It is an arithmetic number, because the mean of its divisors is an integer number (21012975).

Almost surely, 2^84021389 is an apocalyptic number.

It is an amenable number.

84021389 is a deficient number, since it is larger than the sum of its proper divisors (30511).

84021389 is a wasteful number, since it uses less digits than its factorization.

84021389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30510.

The product of its (nonzero) digits is 13824, while the sum is 35.

The square root of 84021389 is about 9166.3181812547. The cubic root of 84021389 is about 437.9890828718.

The spelling of 84021389 in words is "eighty-four million, twenty-one thousand, three hundred eighty-nine".