20647481773 has 16 divisors (see below), whose sum is σ = 21811233600. Its totient is φ = 19491563520.

The previous prime is 20647481749. The next prime is 20647481779. The reversal of 20647481773 is 37718474602.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 20647481773 - 2²¹ = 20645384621 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 (20647481779) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11858683 + ... + 11860423.

It is an arithmetic number, because the mean of its divisors is an integer number (1363202100).

Almost surely, 2^20647481773 is an apocalyptic number.

It is an amenable number.

20647481773 is a deficient number, since it is larger than the sum of its proper divisors (1163751827).

20647481773 is a wasteful number, since it uses less digits than its factorization.

20647481773 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3612.

The product of its (nonzero) digits is 1580544, while the sum is 49.

The spelling of 20647481773 in words is "twenty billion, six hundred forty-seven million, four hundred eighty-one thousand, seven hundred seventy-three".