21702055 has 4 divisors (see below), whose sum is σ = 26042472. Its totient is φ = 17361640.

The previous prime is 21702049. The next prime is 21702059. The reversal of 21702055 is 55020712.

It is a semiprime because it is the product of two primes.

It is a de Polignac number, because none of the positive numbers 2^k-21702055 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21702059) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2170201 + ... + 2170210.

It is an arithmetic number, because the mean of its divisors is an integer number (6510618).

Almost surely, 2^21702055 is an apocalyptic number.

21702055 is a deficient number, since it is larger than the sum of its proper divisors (4340417).

21702055 is an equidigital number, since it uses as much as digits as its factorization.

21702055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4340416.

The product of its (nonzero) digits is 700, while the sum is 22.

The square root of 21702055 is about 4658.5464471228. The cubic root of 21702055 is about 278.9332497054.

Adding to 21702055 its reverse (55020712), we get a palindrome (76722767).

It can be divided in two parts, 2170 and 2055, that added together give a square (4225 = 65²).

The spelling of 21702055 in words is "twenty-one million, seven hundred two thousand, fifty-five".