21353151 has 4 divisors (see below), whose sum is σ = 28470872. Its totient is φ = 14235432.

The previous prime is 21353119. The next prime is 21353153. The reversal of 21353151 is 15135312.

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

It is not a de Polignac number, because 21353151 - 2⁵ = 21353119 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21353153) 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, 3558856 + ... + 3558861.

It is an arithmetic number, because the mean of its divisors is an integer number (7117718).

Almost surely, 2^21353151 is an apocalyptic number.

21353151 is a deficient number, since it is larger than the sum of its proper divisors (7117721).

21353151 is an equidigital number, since it uses as much as digits as its factorization.

21353151 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7117720.

The product of its digits is 450, while the sum is 21.

The square root of 21353151 is about 4620.9469808687. The cubic root of 21353151 is about 277.4303631775.

Adding to 21353151 its reverse (15135312), we get a palindrome (36488463).

The spelling of 21353151 in words is "twenty-one million, three hundred fifty-three thousand, one hundred fifty-one".