21153142 has 4 divisors (see below), whose sum is σ = 31729716. Its totient is φ = 10576570.

The previous prime is 21153133. The next prime is 21153161. The reversal of 21153142 is 24135112.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5288284 + ... + 5288287.

It is an arithmetic number, because the mean of its divisors is an integer number (7932429).

Almost surely, 2^21153142 is an apocalyptic number.

21153142 is a deficient number, since it is larger than the sum of its proper divisors (10576574).

21153142 is a wasteful number, since it uses less digits than its factorization.

21153142 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10576573.

The product of its digits is 240, while the sum is 19.

The square root of 21153142 is about 4599.2545048084. The cubic root of 21153142 is about 276.5614402824.

Adding to 21153142 its reverse (24135112), we get a palindrome (45288254).

The spelling of 21153142 in words is "twenty-one million, one hundred fifty-three thousand, one hundred forty-two".