21310000 has 50 divisors (see below), whose sum is σ = 51617852. Its totient is φ = 8520000.

The previous prime is 21309997. The next prime is 21310007. The reversal of 21310000 is 1312.

It is a tau number, because it is divible by the number of its divisors (50).

It is a super-2 number, since 2×21310000² = 908232200000000, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21310007) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 8935 + ... + 11065.

Almost surely, 2^21310000 is an apocalyptic number.

21310000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21310000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25808926).

21310000 is an abundant number, since it is smaller than the sum of its proper divisors (30307852).

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

21310000 is an equidigital number, since it uses as much as digits as its factorization.

21310000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2159 (or 2138 counting only the distinct ones).

The product of its (nonzero) digits is 6, while the sum is 7.

The square root of 21310000 is about 4616.2755550335. The cubic root of 21310000 is about 277.2433576671.

Adding to 21310000 its reverse (1312), we get a palindrome (21311312).

The spelling of 21310000 in words is "twenty-one million, three hundred ten thousand".