21840102 has 12 divisors (see below), whose sum is σ = 47320260. Its totient is φ = 7280028.

The previous prime is 21840083. The next prime is 21840109. The reversal of 21840102 is 20104812.

It is a Harshad number since it is a multiple of its sum of digits (18), and also a Moran number because the ratio is a prime number: 1213339 = 21840102 / (2 + 1 + 8 + 4 + 0 + 1 + 0 + 2).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21840109) 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 5 ways as a sum of consecutive naturals, for example, 606652 + ... + 606687.

It is an arithmetic number, because the mean of its divisors is an integer number (3943355).

Almost surely, 2^21840102 is an apocalyptic number.

21840102 is an abundant number, since it is smaller than the sum of its proper divisors (25480158).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21840102 is a wasteful number, since it uses less digits than its factorization.

21840102 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1213347 (or 1213344 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

The square root of 21840102 is about 4673.3394911990. The cubic root of 21840102 is about 279.5234325269.

Adding to 21840102 its reverse (20104812), we get a palindrome (41944914).

The spelling of 21840102 in words is "twenty-one million, eight hundred forty thousand, one hundred two".