21523342 has 4 divisors (see below), whose sum is σ = 32285016. Its totient is φ = 10761670.

The previous prime is 21523339. The next prime is 21523351. The reversal of 21523342 is 24332512.

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, 5380834 + ... + 5380837.

It is an arithmetic number, because the mean of its divisors is an integer number (8071254).

Almost surely, 2^21523342 is an apocalyptic number.

21523342 is a deficient number, since it is larger than the sum of its proper divisors (10761674).

21523342 is a wasteful number, since it uses less digits than its factorization.

21523342 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10761673.

The product of its digits is 1440, while the sum is 22.

The square root of 21523342 is about 4639.3255975411. The cubic root of 21523342 is about 278.1654812431.

Adding to 21523342 its reverse (24332512), we get a palindrome (45855854).

The spelling of 21523342 in words is "twenty-one million, five hundred twenty-three thousand, three hundred forty-two".