21340155 has 8 divisors (see below), whose sum is σ = 34144272. Its totient is φ = 11381408.

The previous prime is 21340147. The next prime is 21340171. The reversal of 21340155 is 55104312.

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 21340155 - 2³ = 21340147 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 711324 + ... + 711353.

It is an arithmetic number, because the mean of its divisors is an integer number (4268034).

Almost surely, 2^21340155 is an apocalyptic number.

21340155 is a deficient number, since it is larger than the sum of its proper divisors (12804117).

21340155 is a wasteful number, since it uses less digits than its factorization.

21340155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1422685.

The product of its (nonzero) digits is 600, while the sum is 21.

The square root of 21340155 is about 4619.5405615710. The cubic root of 21340155 is about 277.3740683367.

Adding to 21340155 its reverse (55104312), we get a palindrome (76444467).

The spelling of 21340155 in words is "twenty-one million, three hundred forty thousand, one hundred fifty-five".