20391045 has 16 divisors (see below), whose sum is σ = 32726592. Its totient is φ = 10841600.

The previous prime is 20391043. The next prime is 20391053. The reversal of 20391045 is 54019302.

It is not a de Polignac number, because 20391045 - 2¹ = 20391043 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20391043) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3370 + ... + 7220.

It is an arithmetic number, because the mean of its divisors is an integer number (2045412).

Almost surely, 2^20391045 is an apocalyptic number.

It is an amenable number.

20391045 is a deficient number, since it is larger than the sum of its proper divisors (12335547).

20391045 is a wasteful number, since it uses less digits than its factorization.

20391045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4212.

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 20391045 is about 4515.6444722764. The cubic root of 20391045 is about 273.1994543983.

The spelling of 20391045 in words is "twenty million, three hundred ninety-one thousand, forty-five".