20570740643 has 4 divisors (see below), whose sum is σ = 20574107448. Its totient is φ = 20567373840.

The previous prime is 20570740637. The next prime is 20570740657. The reversal of 20570740643 is 34604707502.

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 20570740643 - 2⁸ = 20570740387 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20570740597 and 20570740606.

It is not an unprimeable number, because it can be changed into a prime (20570740693) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1674221 + ... + 1686462.

It is an arithmetic number, because the mean of its divisors is an integer number (5143526862).

Almost surely, 2^20570740643 is an apocalyptic number.

20570740643 is a deficient number, since it is larger than the sum of its proper divisors (3366805).

20570740643 is an equidigital number, since it uses as much as digits as its factorization.

20570740643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3366804.

The product of its (nonzero) digits is 141120, while the sum is 38.

The spelling of 20570740643 in words is "twenty billion, five hundred seventy million, seven hundred forty thousand, six hundred forty-three".