20953549 has 4 divisors (see below), whose sum is σ = 20963520. Its totient is φ = 20943580.

The previous prime is 20953531. The next prime is 20953553. The reversal of 20953549 is 94535902.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 20953549 - 2⁷ = 20953421 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 (20953579) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 469 + ... + 6490.

It is an arithmetic number, because the mean of its divisors is an integer number (5240880).

Almost surely, 2^20953549 is an apocalyptic number.

It is an amenable number.

20953549 is a deficient number, since it is larger than the sum of its proper divisors (9971).

20953549 is an equidigital number, since it uses as much as digits as its factorization.

20953549 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9970.

The product of its (nonzero) digits is 48600, while the sum is 37.

The square root of 20953549 is about 4577.5046695771. The cubic root of 20953549 is about 275.6888471715.

The spelling of 20953549 in words is "twenty million, nine hundred fifty-three thousand, five hundred forty-nine".