20645356 has 6 divisors (see below), whose sum is σ = 36129380. Its totient is φ = 10322676.

The previous prime is 20645347. The next prime is 20645399. The reversal of 20645356 is 65354602.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2580666 + ... + 2580673.

Almost surely, 2^20645356 is an apocalyptic number.

It is an amenable number.

20645356 is a deficient number, since it is larger than the sum of its proper divisors (15484024).

20645356 is a wasteful number, since it uses less digits than its factorization.

20645356 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5161343 (or 5161341 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 31.

The square root of 20645356 is about 4543.7161002862. The cubic root of 20645356 is about 274.3305191460.

Adding to 20645356 its reverse (65354602), we get a palindrome (85999958).

The spelling of 20645356 in words is "twenty million, six hundred forty-five thousand, three hundred fifty-six".