20906242 has 12 divisors (see below), whose sum is σ = 36479430. Its totient is φ = 8959776.

The previous prime is 20906239. The next prime is 20906257. The reversal of 20906242 is 24260902.

It can be written as a sum of positive squares in only one way, i.e., 14661241 + 6245001 = 3829^2 + 2499^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 106567 + ... + 106762.

Almost surely, 2^20906242 is an apocalyptic number.

20906242 is a deficient number, since it is larger than the sum of its proper divisors (15573188).

20906242 is a wasteful number, since it uses less digits than its factorization.

20906242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213345 (or 213338 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 20906242 is about 4572.3344147164. The cubic root of 20906242 is about 275.4812158431.

The spelling of 20906242 in words is "twenty million, nine hundred six thousand, two hundred forty-two".