20634140 has 12 divisors (see below), whose sum is σ = 43331736. Its totient is φ = 8253648.

The previous prime is 20634101. The next prime is 20634143. The reversal of 20634140 is 4143602.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (20), and also a Moran number because the ratio is a prime number: 1031707 = 20634140 / (2 + 0 + 6 + 3 + 4 + 1 + 4 + 0).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20634143) 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, 515834 + ... + 515873.

It is an arithmetic number, because the mean of its divisors is an integer number (3610978).

Almost surely, 2^20634140 is an apocalyptic number.

20634140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20634140 is an abundant number, since it is smaller than the sum of its proper divisors (22697596).

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

20634140 is a wasteful number, since it uses less digits than its factorization.

20634140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1031716 (or 1031714 counting only the distinct ones).

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

The square root of 20634140 is about 4542.4817005685. The cubic root of 20634140 is about 274.2808316446.

Adding to 20634140 its reverse (4143602), we get a palindrome (24777742).

The spelling of 20634140 in words is "twenty million, six hundred thirty-four thousand, one hundred forty".