21211010 has 16 divisors (see below), whose sum is σ = 38559672. Its totient is φ = 8400000.

The previous prime is 21211009. The next prime is 21211013. The reversal of 21211010 is 1011212.

It can be written as a sum of positive squares in 4 ways, for example, as 19088161 + 2122849 = 4369^2 + 1457^2 .

It is not an unprimeable number, because it can be changed into a prime (21211013) 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 7 ways as a sum of consecutive naturals, for example, 9491 + ... + 11510.

Almost surely, 2^21211010 is an apocalyptic number.

21211010 is a deficient number, since it is larger than the sum of its proper divisors (17348662).

21211010 is a wasteful number, since it uses less digits than its factorization.

21211010 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21109.

The product of its (nonzero) digits is 4, while the sum is 8.

The square root of 21211010 is about 4605.5412276952. The cubic root of 21211010 is about 276.8134042007.

Adding to 21211010 its reverse (1011212), we get a palindrome (22222222).

The spelling of 21211010 in words is "twenty-one million, two hundred eleven thousand, ten".