84021813 has 16 divisors (see below), whose sum is σ = 125979840. Its totient is φ = 55338192.

The previous prime is 84021761. The next prime is 84021823. The reversal of 84021813 is 31812048.

It is not a de Polignac number, because 84021813 - 2²⁵ = 50467381 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (84021823) 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, 16506 + ... + 20987.

It is an arithmetic number, because the mean of its divisors is an integer number (7873740).

Almost surely, 2^84021813 is an apocalyptic number.

84021813 is a gapful number since it is divisible by the number (83) formed by its first and last digit.

It is an amenable number.

84021813 is a deficient number, since it is larger than the sum of its proper divisors (41958027).

84021813 is a wasteful number, since it uses less digits than its factorization.

84021813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37585 (or 37579 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The square root of 84021813 is about 9166.3413093775. The cubic root of 84021813 is about 437.9898196170.

The spelling of 84021813 in words is "eighty-four million, twenty-one thousand, eight hundred thirteen".