21701205 has 24 divisors (see below), whose sum is σ = 37975392. Its totient is φ = 11463264.

The previous prime is 21701201. The next prime is 21701219. The reversal of 21701205 is 50210712.

It is not a de Polignac number, because 21701205 - 2² = 21701201 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21701201) 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 23 ways as a sum of consecutive naturals, for example, 2562 + ... + 7068.

It is an arithmetic number, because the mean of its divisors is an integer number (1582308).

Almost surely, 2^21701205 is an apocalyptic number.

It is an amenable number.

21701205 is a deficient number, since it is larger than the sum of its proper divisors (16274187).

21701205 is a wasteful number, since it uses less digits than its factorization.

21701205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4625 (or 4622 counting only the distinct ones).

The product of its (nonzero) digits is 140, while the sum is 18.

The square root of 21701205 is about 4658.4552160561. The cubic root of 21701205 is about 278.9296080171.

Adding to 21701205 its reverse (50210712), we get a palindrome (71911917).

It can be divided in two parts, 2170 and 1205, that added together give a cube (3375 = 15³).

The spelling of 21701205 in words is "twenty-one million, seven hundred one thousand, two hundred five".