20929139 has 8 divisors (see below), whose sum is σ = 26093568. Its totient is φ = 16308360.

The previous prime is 20929121. The next prime is 20929141. The reversal of 20929139 is 93192902.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20929139 - 2¹² = 20925043 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20929099 and 20929108.

It is not an unprimeable number, because it can be changed into a prime (20929109) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 135827 + ... + 135980.

It is an arithmetic number, because the mean of its divisors is an integer number (3261696).

Almost surely, 2^20929139 is an apocalyptic number.

20929139 is a deficient number, since it is larger than the sum of its proper divisors (5164429).

20929139 is a wasteful number, since it uses less digits than its factorization.

20929139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 271825.

The product of its (nonzero) digits is 8748, while the sum is 35.

The square root of 20929139 is about 4574.8375927458. The cubic root of 20929139 is about 275.5817502835.

The spelling of 20929139 in words is "twenty million, nine hundred twenty-nine thousand, one hundred thirty-nine".