21662153 has 4 divisors (see below), whose sum is σ = 22165968. Its totient is φ = 21158340.

The previous prime is 21662129. The next prime is 21662189. The reversal of 21662153 is 35126612.

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 21662153 - 2²⁴ = 4884937 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21662453) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 251843 + ... + 251928.

It is an arithmetic number, because the mean of its divisors is an integer number (5541492).

Almost surely, 2^21662153 is an apocalyptic number.

It is an amenable number.

21662153 is a deficient number, since it is larger than the sum of its proper divisors (503815).

21662153 is an equidigital number, since it uses as much as digits as its factorization.

21662153 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 503814.

The product of its digits is 2160, while the sum is 26.

The square root of 21662153 is about 4654.2618104271. The cubic root of 21662153 is about 278.7621933575.

Adding to 21662153 its reverse (35126612), we get a palindrome (56788765).

The spelling of 21662153 in words is "twenty-one million, six hundred sixty-two thousand, one hundred fifty-three".