20795123749 has 4 divisors (see below), whose sum is σ = 20795503564. Its totient is φ = 20794743936.

The previous prime is 20795123737. The next prime is 20795123753. The reversal of 20795123749 is 94732159702.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 15532636900 + 5262486849 = 124630^2 + 72543^2 .

It is a cyclic number.

It is not a de Polignac number, because 20795123749 - 2⁵ = 20795123717 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 (20795153749) 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, 90402 + ... + 223075.

It is an arithmetic number, because the mean of its divisors is an integer number (5198875891).

Almost surely, 2^20795123749 is an apocalyptic number.

It is an amenable number.

20795123749 is a deficient number, since it is larger than the sum of its proper divisors (379815).

20795123749 is an equidigital number, since it uses as much as digits as its factorization.

20795123749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 379814.

The product of its (nonzero) digits is 952560, while the sum is 49.

The spelling of 20795123749 in words is "twenty billion, seven hundred ninety-five million, one hundred twenty-three thousand, seven hundred forty-nine".