20391434 has 16 divisors (see below), whose sum is σ = 35014848. Its totient is φ = 8724672.

The previous prime is 20391433. The next prime is 20391443. The reversal of 20391434 is 43419302.

It is a super-3 number, since 3×20391434³ (a number of 23 digits) contains 333 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20391431) 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 7 ways as a sum of consecutive naturals, for example, 15074 + ... + 16370.

It is an arithmetic number, because the mean of its divisors is an integer number (2188428).

Almost surely, 2^20391434 is an apocalyptic number.

20391434 is a deficient number, since it is larger than the sum of its proper divisors (14623414).

20391434 is a wasteful number, since it uses less digits than its factorization.

20391434 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2429.

The product of its (nonzero) digits is 2592, while the sum is 26.

The square root of 20391434 is about 4515.6875445496. The cubic root of 20391434 is about 273.2011916628.

The spelling of 20391434 in words is "twenty million, three hundred ninety-one thousand, four hundred thirty-four".