20644742 has 16 divisors (see below), whose sum is σ = 31970160. Its totient is φ = 9991008.

The previous prime is 20644733. The next prime is 20644751. The reversal of 20644742 is 24744602.

It is an interprime number because it is at equal distance from previous prime (20644733) and next prime (20644751).

It is a congruent number.

It is an unprimeable number.

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, 16184 + ... + 17412.

It is an arithmetic number, because the mean of its divisors is an integer number (1998135).

Almost surely, 2^20644742 is an apocalyptic number.

20644742 is a deficient number, since it is larger than the sum of its proper divisors (11325418).

20644742 is a wasteful number, since it uses less digits than its factorization.

20644742 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1495.

The product of its (nonzero) digits is 10752, while the sum is 29.

The square root of 20644742 is about 4543.6485339427. The cubic root of 20644742 is about 274.3277995577.

The spelling of 20644742 in words is "twenty million, six hundred forty-four thousand, seven hundred forty-two".