84650021 has 4 divisors (see below), whose sum is σ = 89629452. Its totient is φ = 79670592.

The previous prime is 84650003. The next prime is 84650047. The reversal of 84650021 is 12005648.

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 46036225 + 38613796 = 6785^2 + 6214^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-84650021 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 (84650821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2489690 + ... + 2489723.

It is an arithmetic number, because the mean of its divisors is an integer number (22407363).

Almost surely, 2^84650021 is an apocalyptic number.

It is an amenable number.

84650021 is a deficient number, since it is larger than the sum of its proper divisors (4979431).

84650021 is a wasteful number, since it uses less digits than its factorization.

84650021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4979430.

The product of its (nonzero) digits is 1920, while the sum is 26.

The square root of 84650021 is about 9200.5446034460. The cubic root of 84650021 is about 439.0786868844.

Adding to 84650021 its reverse (12005648), we get a palindrome (96655669).

The spelling of 84650021 in words is "eighty-four million, six hundred fifty thousand, twenty-one".