20406542 has 8 divisors (see below), whose sum is σ = 32964456. Its totient is φ = 9418392.

The previous prime is 20406539. The next prime is 20406559. The reversal of 20406542 is 24560402.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 392408 + ... + 392459.

It is an arithmetic number, because the mean of its divisors is an integer number (4120557).

Almost surely, 2^20406542 is an apocalyptic number.

20406542 is a deficient number, since it is larger than the sum of its proper divisors (12557914).

20406542 is a wasteful number, since it uses less digits than its factorization.

20406542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 784882.

The product of its (nonzero) digits is 1920, while the sum is 23.

The square root of 20406542 is about 4517.3600697753. The cubic root of 20406542 is about 273.2686465340.

Adding to 20406542 its reverse (24560402), we get a palindrome (44966944).

The spelling of 20406542 in words is "twenty million, four hundred six thousand, five hundred forty-two".