21870010 has 16 divisors (see below), whose sum is σ = 41078016. Its totient is φ = 8367568.

The previous prime is 21869999. The next prime is 21870011. The reversal of 21870010 is 1007812.

It is a self number, because there is not a number n which added to its sum of digits gives 21870010.

It is not an unprimeable number, because it can be changed into a prime (21870011) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47314 + ... + 47773.

It is an arithmetic number, because the mean of its divisors is an integer number (2567376).

Almost surely, 2^21870010 is an apocalyptic number.

21870010 is a deficient number, since it is larger than the sum of its proper divisors (19208006).

21870010 is a wasteful number, since it uses less digits than its factorization.

21870010 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95117.

The product of its (nonzero) digits is 112, while the sum is 19.

The square root of 21870010 is about 4676.5382496030. The cubic root of 21870010 is about 279.6509681591.

Adding to 21870010 its reverse (1007812), we get a palindrome (22877822).

The spelling of 21870010 in words is "twenty-one million, eight hundred seventy thousand, ten".