20505442 has 8 divisors (see below), whose sum is σ = 31412736. Its totient is φ = 10034532.

The previous prime is 20505431. The next prime is 20505449. The reversal of 20505442 is 24450502.

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

It is not an unprimeable number, because it can be changed into a prime (20505449) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 108978 + ... + 109165.

It is an arithmetic number, because the mean of its divisors is an integer number (3926592).

Almost surely, 2^20505442 is an apocalyptic number.

20505442 is a deficient number, since it is larger than the sum of its proper divisors (10907294).

20505442 is a wasteful number, since it uses less digits than its factorization.

20505442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218192.

The product of its (nonzero) digits is 1600, while the sum is 22.

The square root of 20505442 is about 4528.2934975551. The cubic root of 20505442 is about 273.7093993984.

Adding to 20505442 its reverse (24450502), we get a palindrome (44955944).

The spelling of 20505442 in words is "twenty million, five hundred five thousand, four hundred forty-two".