20431155 has 16 divisors (see below), whose sum is σ = 32820480. Its totient is φ = 10853088.

The previous prime is 20431123. The next prime is 20431171. The reversal of 20431155 is 55113402.

It is not a de Polignac number, because 20431155 - 2⁵ = 20431123 is a prime.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 1356 + ... + 6534.

It is an arithmetic number, because the mean of its divisors is an integer number (2051280).

Almost surely, 2^20431155 is an apocalyptic number.

20431155 is a deficient number, since it is larger than the sum of its proper divisors (12389325).

20431155 is a wasteful number, since it uses less digits than its factorization.

20431155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5450.

The product of its (nonzero) digits is 600, while the sum is 21.

The square root of 20431155 is about 4520.0835169275. The cubic root of 20431155 is about 273.3784684867.

Adding to 20431155 its reverse (55113402), we get a palindrome (75544557).

The spelling of 20431155 in words is "twenty million, four hundred thirty-one thousand, one hundred fifty-five".