20496961643 has 4 divisors (see below), whose sum is σ = 20499625440. Its totient is φ = 20494297848.

The previous prime is 20496961627. The next prime is 20496961657. The reversal of 20496961643 is 34616969402.

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 20496961643 - 2⁴ = 20496961627 is a prime.

It is a super-2 number, since 2×20496961643² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20496961591 and 20496961600.

It is not an unprimeable number, because it can be changed into a prime (20496961343) 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, 1320323 + ... + 1335756.

It is an arithmetic number, because the mean of its divisors is an integer number (5124906360).

Almost surely, 2^20496961643 is an apocalyptic number.

20496961643 is a deficient number, since it is larger than the sum of its proper divisors (2663797).

20496961643 is an equidigital number, since it uses as much as digits as its factorization.

20496961643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2663796.

The product of its (nonzero) digits is 1679616, while the sum is 50.

The spelling of 20496961643 in words is "twenty billion, four hundred ninety-six million, nine hundred sixty-one thousand, six hundred forty-three".