21153242 has 8 divisors (see below), whose sum is σ = 34614432. Its totient is φ = 9615100.

The previous prime is 21153227. The next prime is 21153257. The reversal of 21153242 is 24235112.

It is an interprime number because it is at equal distance from previous prime (21153227) and next prime (21153257).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×21153242² = 894919294221128, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 480734 + ... + 480777.

It is an arithmetic number, because the mean of its divisors is an integer number (4326804).

Almost surely, 2^21153242 is an apocalyptic number.

21153242 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21153242 is a deficient number, since it is larger than the sum of its proper divisors (13461190).

21153242 is a wasteful number, since it uses less digits than its factorization.

21153242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 961524.

The product of its digits is 480, while the sum is 20.

The square root of 21153242 is about 4599.2653761226. The cubic root of 21153242 is about 276.5618760900.

Adding to 21153242 its reverse (24235112), we get a palindrome (45388354).

The spelling of 21153242 in words is "twenty-one million, one hundred fifty-three thousand, two hundred forty-two".