21154344 has 32 divisors (see below), whose sum is σ = 53171520. Its totient is φ = 7013376.

The previous prime is 21154339. The next prime is 21154381. The reversal of 21154344 is 44345112.

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

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2349 + ... + 6915.

It is an arithmetic number, because the mean of its divisors is an integer number (1661610).

Almost surely, 2^21154344 is an apocalyptic number.

21154344 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21154344 is an abundant number, since it is smaller than the sum of its proper divisors (32017176).

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

21154344 is a wasteful number, since it uses less digits than its factorization.

21154344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4769 (or 4765 counting only the distinct ones).

The product of its digits is 1920, while the sum is 24.

The square root of 21154344 is about 4599.3851763035. The cubic root of 21154344 is about 276.5666785988.

Adding to 21154344 its reverse (44345112), we get a palindrome (65499456).

The spelling of 21154344 in words is "twenty-one million, one hundred fifty-four thousand, three hundred forty-four".