20641649783 has 4 divisors (see below), whose sum is σ = 21353430840. Its totient is φ = 19929868728.

The previous prime is 20641649767. The next prime is 20641649797. The reversal of 20641649783 is 38794614602.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20641649783 - 2⁴ = 20641649767 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20641649683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 355890485 + ... + 355890542.

It is an arithmetic number, because the mean of its divisors is an integer number (5338357710).

Almost surely, 2^20641649783 is an apocalyptic number.

20641649783 is a deficient number, since it is larger than the sum of its proper divisors (711781057).

20641649783 is an equidigital number, since it uses as much as digits as its factorization.

20641649783 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 711781056.

The product of its (nonzero) digits is 1741824, while the sum is 50.

The spelling of 20641649783 in words is "twenty billion, six hundred forty-one million, six hundred forty-nine thousand, seven hundred eighty-three".