20657299807 has 4 divisors (see below), whose sum is σ = 21369620520. Its totient is φ = 19944979096.

The previous prime is 20657299759. The next prime is 20657299823. The reversal of 20657299807 is 70899275602.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20657299807 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 (20657297807) 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, 356160313 + ... + 356160370.

It is an arithmetic number, because the mean of its divisors is an integer number (5342405130).

Almost surely, 2^20657299807 is an apocalyptic number.

20657299807 is a deficient number, since it is larger than the sum of its proper divisors (712320713).

20657299807 is an equidigital number, since it uses as much as digits as its factorization.

20657299807 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 712320712.

The product of its (nonzero) digits is 3810240, while the sum is 55.

The spelling of 20657299807 in words is "twenty billion, six hundred fifty-seven million, two hundred ninety-nine thousand, eight hundred seven".