21000348 has 72 divisors (see below), whose sum is σ = 55111056. Its totient is φ = 6739200.

The previous prime is 21000337. The next prime is 21000367. The reversal of 21000348 is 84300012.

It is a happy number.

It is a super-2 number, since 2×21000348² = 882029232242208, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a self number, because there is not a number n which added to its sum of digits gives 21000348.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 160243 + ... + 160373.

Almost surely, 2^21000348 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21000348, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27555528).

21000348 is an abundant number, since it is smaller than the sum of its proper divisors (34110708).

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

21000348 is a wasteful number, since it uses less digits than its factorization.

21000348 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 275 (or 270 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 21000348 is about 4582.6136647114. The cubic root of 21000348 is about 275.8939416069.

The spelling of 21000348 in words is "twenty-one million, three hundred forty-eight", and thus it is an aban number.