21023376 has 80 divisors (see below), whose sum is σ = 61335360. Its totient is φ = 6146560.

The previous prime is 21023341. The next prime is 21023381. The reversal of 21023376 is 67332012.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14626 + ... + 15998.

It is an arithmetic number, because the mean of its divisors is an integer number (766692).

Almost surely, 2^21023376 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 21023376, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30667680).

21023376 is an abundant number, since it is smaller than the sum of its proper divisors (40311984).

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

21023376 is a wasteful number, since it uses less digits than its factorization.

21023376 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1424 (or 1418 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 24.

The square root of 21023376 is about 4585.1255162754. The cubic root of 21023376 is about 275.9947489024.

Adding to 21023376 its reverse (67332012), we get a palindrome (88355388).

The spelling of 21023376 in words is "twenty-one million, twenty-three thousand, three hundred seventy-six".