21534442 has 8 divisors (see below), whose sum is σ = 32756832. Its totient is φ = 10615500.

The previous prime is 21534437. The next prime is 21534451. The reversal of 21534442 is 24443512.

It is a happy number.

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

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, 75684 + ... + 75967.

It is an arithmetic number, because the mean of its divisors is an integer number (4094604).

Almost surely, 2^21534442 is an apocalyptic number.

21534442 is a deficient number, since it is larger than the sum of its proper divisors (11222390).

21534442 is a wasteful number, since it uses less digits than its factorization.

21534442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151724.

The product of its digits is 3840, while the sum is 25.

The square root of 21534442 is about 4640.5217379084. The cubic root of 21534442 is about 278.2132914486.

Adding to 21534442 its reverse (24443512), we get a palindrome (45977954).

The spelling of 21534442 in words is "twenty-one million, five hundred thirty-four thousand, four hundred forty-two".