21021410 has 64 divisors (see below), whose sum is σ = 42577920. Its totient is φ = 7439040.

The previous prime is 21021389. The next prime is 21021419. The reversal of 21021410 is 1412012.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21021391 and 21021400.

It is not an unprimeable number, because it can be changed into a prime (21021419) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 253229 + ... + 253311.

It is an arithmetic number, because the mean of its divisors is an integer number (665280).

Almost surely, 2^21021410 is an apocalyptic number.

21021410 is an abundant number, since it is smaller than the sum of its proper divisors (21556510).

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

21021410 is a wasteful number, since it uses less digits than its factorization.

21021410 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 183.

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 21021410 is about 4584.9111223665. The cubic root of 21021410 is about 275.9861454223.

Adding to 21021410 its reverse (1412012), we get a palindrome (22433422).

The spelling of 21021410 in words is "twenty-one million, twenty-one thousand, four hundred ten".