21023352 has 144 divisors (see below), whose sum is σ = 68023800. Its totient is φ = 5846400.

The previous prime is 21023341. The next prime is 21023381. The reversal of 21023352 is 25332012.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 208102 + ... + 208202.

Almost surely, 2^21023352 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 21023352, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34011900).

21023352 is an abundant number, since it is smaller than the sum of its proper divisors (47000448).

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

21023352 is a wasteful number, since it uses less digits than its factorization.

21023352 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 186 (or 172 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 18.

The square root of 21023352 is about 4585.1228991162. The cubic root of 21023352 is about 275.9946438784.

Adding to 21023352 its reverse (25332012), we get a palindrome (46355364).

The spelling of 21023352 in words is "twenty-one million, twenty-three thousand, three hundred fifty-two".