20473787457 has 6 divisors (see below), whose sum is σ = 29573248562. Its totient is φ = 13649191632.

The previous prime is 20473787423. The next prime is 20473787471. The reversal of 20473787457 is 75478737402.

It can be written as a sum of positive squares in only one way, i.e., 15398079921 + 5075707536 = 124089^2 + 71244^2 .

It is not a de Polignac number, because 20473787457 - 2⁷ = 20473787329 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20473787657) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1137432628 + ... + 1137432645.

Almost surely, 2^20473787457 is an apocalyptic number.

It is an amenable number.

20473787457 is a deficient number, since it is larger than the sum of its proper divisors (9099461105).

20473787457 is a wasteful number, since it uses less digits than its factorization.

20473787457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2274865279 (or 2274865276 counting only the distinct ones).

The product of its (nonzero) digits is 9219840, while the sum is 54.

The spelling of 20473787457 in words is "twenty billion, four hundred seventy-three million, seven hundred eighty-seven thousand, four hundred fifty-seven".