21320153 has 4 divisors (see below), whose sum is σ = 21439440. Its totient is φ = 21200868.

The previous prime is 21320107. The next prime is 21320183. The reversal of 21320153 is 35102312.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21320153 - 2¹⁶ = 21254617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21320183) 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, 59375 + ... + 59732.

It is an arithmetic number, because the mean of its divisors is an integer number (5359860).

Almost surely, 2^21320153 is an apocalyptic number.

It is an amenable number.

21320153 is a deficient number, since it is larger than the sum of its proper divisors (119287).

21320153 is a wasteful number, since it uses less digits than its factorization.

21320153 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119286.

The product of its (nonzero) digits is 180, while the sum is 17.

The square root of 21320153 is about 4617.3751201305. The cubic root of 21320153 is about 277.2873808939.

Adding to 21320153 its reverse (35102312), we get a palindrome (56422465).

The spelling of 21320153 in words is "twenty-one million, three hundred twenty thousand, one hundred fifty-three".