20402439 has 8 divisors (see below), whose sum is σ = 27457920. Its totient is φ = 13474296.

The previous prime is 20402419. The next prime is 20402441. The reversal of 20402439 is 93420402.

It is a happy number.

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

It is not a de Polignac number, because 20402439 - 2⁵ = 20402407 is a prime.

20402439 is a modest number, since divided by 2439 gives 204 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20402419) 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, 31459 + ... + 32100.

It is an arithmetic number, because the mean of its divisors is an integer number (3432240).

Almost surely, 2^20402439 is an apocalyptic number.

20402439 is a deficient number, since it is larger than the sum of its proper divisors (7055481).

20402439 is a wasteful number, since it uses less digits than its factorization.

20402439 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63669.

The product of its (nonzero) digits is 1728, while the sum is 24.

The square root of 20402439 is about 4516.9059100229. The cubic root of 20402439 is about 273.2503305709.

The spelling of 20402439 in words is "twenty million, four hundred two thousand, four hundred thirty-nine".