20774891785 has 4 divisors (see below), whose sum is σ = 24929870148. Its totient is φ = 16619913424.

The previous prime is 20774891777. The next prime is 20774891827. The reversal of 20774891785 is 58719847702.

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 6032318224 + 14742573561 = 77668^2 + 121419^2 .

It is a cyclic number.

It is not a de Polignac number, because 20774891785 - 2³ = 20774891777 is a prime.

It is a super-2 number, since 2×20774891785² (a number of 21 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2077489174 + ... + 2077489183.

It is an arithmetic number, because the mean of its divisors is an integer number (6232467537).

Almost surely, 2^20774891785 is an apocalyptic number.

It is an amenable number.

20774891785 is a deficient number, since it is larger than the sum of its proper divisors (4154978363).

20774891785 is an equidigital number, since it uses as much as digits as its factorization.

20774891785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4154978362.

The product of its (nonzero) digits is 7902720, while the sum is 58.

The spelling of 20774891785 in words is "twenty billion, seven hundred seventy-four million, eight hundred ninety-one thousand, seven hundred eighty-five".