21342155 has 8 divisors (see below), whose sum is σ = 26302992. Its totient is φ = 16612128.

The previous prime is 21342143. The next prime is 21342161. The reversal of 21342155 is 55124312.

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

It is a cyclic number.

It is not a de Polignac number, because 21342155 - 2¹² = 21338059 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21342155.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 57497 + ... + 57866.

It is an arithmetic number, because the mean of its divisors is an integer number (3287874).

Almost surely, 2^21342155 is an apocalyptic number.

21342155 is a deficient number, since it is larger than the sum of its proper divisors (4960837).

21342155 is a wasteful number, since it uses less digits than its factorization.

21342155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115405.

The product of its digits is 1200, while the sum is 23.

The square root of 21342155 is about 4619.7570282429. The cubic root of 21342155 is about 277.3827332348.

Adding to 21342155 its reverse (55124312), we get a palindrome (76466467).

The spelling of 21342155 in words is "twenty-one million, three hundred forty-two thousand, one hundred fifty-five".