21511342 has 8 divisors (see below), whose sum is σ = 32297256. Its totient is φ = 10745592.

The previous prime is 21511337. The next prime is 21511349. The reversal of 21511342 is 24311512.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21511349) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2008 + ... + 6859.

It is an arithmetic number, because the mean of its divisors is an integer number (4037157).

Almost surely, 2^21511342 is an apocalyptic number.

21511342 is a deficient number, since it is larger than the sum of its proper divisors (10785914).

21511342 is a wasteful number, since it uses less digits than its factorization.

21511342 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10082.

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

The square root of 21511342 is about 4638.0321258051. The cubic root of 21511342 is about 278.1137760399.

Adding to 21511342 its reverse (24311512), we get a palindrome (45822854).

The spelling of 21511342 in words is "twenty-one million, five hundred eleven thousand, three hundred forty-two".