20135439 has 8 divisors (see below), whose sum is σ = 29830320. Its totient is φ = 13423608.

The previous prime is 20135431. The next prime is 20135447. The reversal of 20135439 is 93453102.

It is an interprime number because it is at equal distance from previous prime (20135431) and next prime (20135447).

It is not a de Polignac number, because 20135439 - 2³ = 20135431 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 745757 = 20135439 / (2 + 0 + 1 + 3 + 5 + 4 + 3 + 9).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20135431) 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, 372852 + ... + 372905.

It is an arithmetic number, because the mean of its divisors is an integer number (3728790).

Almost surely, 2^20135439 is an apocalyptic number.

20135439 is a deficient number, since it is larger than the sum of its proper divisors (9694881).

20135439 is an equidigital number, since it uses as much as digits as its factorization.

20135439 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 745766 (or 745760 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 27.

The square root of 20135439 is about 4487.2529458456. The cubic root of 20135439 is about 272.0531137267.

The spelling of 20135439 in words is "twenty million, one hundred thirty-five thousand, four hundred thirty-nine".