21802153 has 4 divisors (see below), whose sum is σ = 21827728. Its totient is φ = 21776580.

The previous prime is 21802141. The next prime is 21802159. The reversal of 21802153 is 35120812.

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 21802153 - 2⁹ = 21801641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21802159) 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, 11463 + ... + 13228.

It is an arithmetic number, because the mean of its divisors is an integer number (5456932).

Almost surely, 2^21802153 is an apocalyptic number.

It is an amenable number.

21802153 is a deficient number, since it is larger than the sum of its proper divisors (25575).

21802153 is an equidigital number, since it uses as much as digits as its factorization.

21802153 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25574.

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 21802153 is about 4669.2775672474. The cubic root of 21802153 is about 279.3614402346.

Adding to 21802153 its reverse (35120812), we get a palindrome (56922965).

The spelling of 21802153 in words is "twenty-one million, eight hundred two thousand, one hundred fifty-three".