20457531761 has 4 divisors (see below), whose sum is σ = 20457819300. Its totient is φ = 20457244224.

The previous prime is 20457531727. The next prime is 20457531767. The reversal of 20457531761 is 16713575402.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 16713575402 = 2 ⋅8356787701.

It can be written as a sum of positive squares in 2 ways, for example, as 9246745600 + 11210786161 = 96160^2 + 105881^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20457531761 is a prime.

It is a super-2 number, since 2×20457531761² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20457531767) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 50045 + ... + 208373.

It is an arithmetic number, because the mean of its divisors is an integer number (5114454825).

Almost surely, 2^20457531761 is an apocalyptic number.

It is an amenable number.

20457531761 is a deficient number, since it is larger than the sum of its proper divisors (287539).

20457531761 is a wasteful number, since it uses less digits than its factorization.

20457531761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 287538.

The product of its (nonzero) digits is 176400, while the sum is 41.

The spelling of 20457531761 in words is "twenty billion, four hundred fifty-seven million, five hundred thirty-one thousand, seven hundred sixty-one".