21965253 has 8 divisors (see below), whose sum is σ = 30560448. Its totient is φ = 14006784.

The previous prime is 21965249. The next prime is 21965351. The reversal of 21965253 is 35256912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21965253 - 2² = 21965249 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21965233) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 159100 + ... + 159237.

It is an arithmetic number, because the mean of its divisors is an integer number (3820056).

Almost surely, 2^21965253 is an apocalyptic number.

21965253 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21965253 is a deficient number, since it is larger than the sum of its proper divisors (8595195).

21965253 is a wasteful number, since it uses less digits than its factorization.

21965253 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 318363.

The product of its digits is 16200, while the sum is 33.

The square root of 21965253 is about 4686.7102534720. The cubic root of 21965253 is about 280.0563364534.

The spelling of 21965253 in words is "twenty-one million, nine hundred sixty-five thousand, two hundred fifty-three".