21325155 has 8 divisors (see below), whose sum is σ = 34120272. Its totient is φ = 11373408.

The previous prime is 21325151. The next prime is 21325177. The reversal of 21325155 is 55152312.

It is a happy number.

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

It is not a de Polignac number, because 21325155 - 2² = 21325151 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21325151) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 710824 + ... + 710853.

It is an arithmetic number, because the mean of its divisors is an integer number (4265034).

Almost surely, 2^21325155 is an apocalyptic number.

21325155 is a deficient number, since it is larger than the sum of its proper divisors (12795117).

21325155 is a wasteful number, since it uses less digits than its factorization.

21325155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1421685.

The product of its digits is 1500, while the sum is 24.

The square root of 21325155 is about 4617.9167380974. The cubic root of 21325155 is about 277.3090643378.

Adding to 21325155 its reverse (55152312), we get a palindrome (76477467).

The spelling of 21325155 in words is "twenty-one million, three hundred twenty-five thousand, one hundred fifty-five".