20134640 has 40 divisors (see below), whose sum is σ = 47005920. Its totient is φ = 8020736.

The previous prime is 20134633. The next prime is 20134643. The reversal of 20134640 is 4643102.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20134643) 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 7 ways as a sum of consecutive naturals, for example, 30797 + ... + 31443.

It is an arithmetic number, because the mean of its divisors is an integer number (1175148).

Almost surely, 2^20134640 is an apocalyptic number.

20134640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20134640 is an abundant number, since it is smaller than the sum of its proper divisors (26871280).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20134640 is a wasteful number, since it uses less digits than its factorization.

20134640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1049 (or 1043 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 20134640 is about 4487.1639149913. The cubic root of 20134640 is about 272.0495152071.

Adding to 20134640 its reverse (4643102), we get a palindrome (24777742).

The spelling of 20134640 in words is "twenty million, one hundred thirty-four thousand, six hundred forty".