20553091 has 4 divisors (see below), whose sum is σ = 22134112. Its totient is φ = 18972072.

The previous prime is 20553089. The next prime is 20553107. The reversal of 20553091 is 19035502.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20553091 - 2¹ = 20553089 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20553691) 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 3 ways as a sum of consecutive naturals, for example, 790491 + ... + 790516.

It is an arithmetic number, because the mean of its divisors is an integer number (5533528).

Almost surely, 2^20553091 is an apocalyptic number.

20553091 is a deficient number, since it is larger than the sum of its proper divisors (1581021).

20553091 is a wasteful number, since it uses less digits than its factorization.

20553091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1581020.

The product of its (nonzero) digits is 1350, while the sum is 25.

The square root of 20553091 is about 4533.5516981722. The cubic root of 20553091 is about 273.9212438152.

Adding to 20553091 its reverse (19035502), we get a palindrome (39588593).

The spelling of 20553091 in words is "twenty million, five hundred fifty-three thousand, ninety-one".