21782453057 has 2 divisors, whose sum is σ = 21782453058. Its totient is φ = 21782453056.

The previous prime is 21782453047. The next prime is 21782453129. The reversal of 21782453057 is 75035428712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15807781441 + 5974671616 = 125729^2 + 77296^2 .

It is a cyclic number.

It is not a de Polignac number, because 21782453057 - 2⁴ = 21782453041 is a prime.

It is a super-2 number, since 2×21782453057² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21782452999 and 21782453017.

It is not a weakly prime, because it can be changed into another prime (21782453047) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10891226528 + 10891226529.

It is an arithmetic number, because the mean of its divisors is an integer number (10891226529).

Almost surely, 2^21782453057 is an apocalyptic number.

It is an amenable number.

21782453057 is a deficient number, since it is larger than the sum of its proper divisors (1).

21782453057 is an equidigital number, since it uses as much as digits as its factorization.

21782453057 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 470400, while the sum is 44.

The spelling of 21782453057 in words is "twenty-one billion, seven hundred eighty-two million, four hundred fifty-three thousand, fifty-seven".