20139742 has 16 divisors (see below), whose sum is σ = 34588512. Its totient is φ = 8615520.

The previous prime is 20139737. The next prime is 20139773. The reversal of 20139742 is 24793102.

It is a self number, because there is not a number n which added to its sum of digits gives 20139742.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9892 + ... + 11752.

It is an arithmetic number, because the mean of its divisors is an integer number (2161782).

Almost surely, 2^20139742 is an apocalyptic number.

20139742 is a deficient number, since it is larger than the sum of its proper divisors (14448770).

20139742 is a wasteful number, since it uses less digits than its factorization.

20139742 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2643.

The product of its (nonzero) digits is 3024, while the sum is 28.

The square root of 20139742 is about 4487.7323895259. The cubic root of 20139742 is about 272.0724918518.

The spelling of 20139742 in words is "twenty million, one hundred thirty-nine thousand, seven hundred forty-two".