20704139 has 8 divisors (see below), whose sum is σ = 21528528. Its totient is φ = 19895040.

The previous prime is 20704093. The next prime is 20704141. The reversal of 20704139 is 93140702.

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 20704139 - 2¹⁶ = 20638603 is a prime.

It is a super-2 number, since 2×20704139² = 857322743462642, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20704639) 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, 1022 + ... + 6515.

It is an arithmetic number, because the mean of its divisors is an integer number (2691066).

Almost surely, 2^20704139 is an apocalyptic number.

20704139 is a deficient number, since it is larger than the sum of its proper divisors (824389).

20704139 is an equidigital number, since it uses as much as digits as its factorization.

20704139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7645.

The product of its (nonzero) digits is 1512, while the sum is 26.

The square root of 20704139 is about 4550.1801063255. The cubic root of 20704139 is about 274.5906372092.

It can be divided in two parts, 2070 and 4139, that multiplied together give a triangular number (8567730 = T₄₁₃₉).

The spelling of 20704139 in words is "twenty million, seven hundred four thousand, one hundred thirty-nine".