21361151 has 4 divisors (see below), whose sum is σ = 24412752. Its totient is φ = 18309552.

The previous prime is 21361147. The next prime is 21361169. The reversal of 21361151 is 15116312.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21361151 - 2² = 21361147 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21361121) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 1525790 + ... + 1525803.

It is an arithmetic number, because the mean of its divisors is an integer number (6103188).

Almost surely, 2^21361151 is an apocalyptic number.

21361151 is a deficient number, since it is larger than the sum of its proper divisors (3051601).

21361151 is an equidigital number, since it uses as much as digits as its factorization.

21361151 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3051600.

The product of its digits is 180, while the sum is 20.

The square root of 21361151 is about 4621.8125232424. The cubic root of 21361151 is about 277.4650054619.

Adding to 21361151 its reverse (15116312), we get a palindrome (36477463).

It can be divided in two parts, 21361 and 151, that added together give a palindrome (21512).

The spelling of 21361151 in words is "twenty-one million, three hundred sixty-one thousand, one hundred fifty-one".