1061645581 has 2 divisors, whose sum is σ = 1061645582. Its totient is φ = 1061645580.

The previous prime is 1061645567. The next prime is 1061645593. The reversal of 1061645581 is 1855461601.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1001722500 + 59923081 = 31650^2 + 7741^2 .

It is a cyclic number.

It is not a de Polignac number, because 1061645581 - 2⁹ = 1061645069 is a prime.

It is a super-2 number, since 2×1061645581² = 2254182679313655122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1061645581.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1061645521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 530822790 + 530822791.

It is an arithmetic number, because the mean of its divisors is an integer number (530822791).

Almost surely, 2^1061645581 is an apocalyptic number.

It is an amenable number.

1061645581 is a deficient number, since it is larger than the sum of its proper divisors (1).

1061645581 is an equidigital number, since it uses as much as digits as its factorization.

1061645581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 28800, while the sum is 37.

The square root of 1061645581 is about 32582.9032009120. The cubic root of 1061645581 is about 1020.1401771336.

The spelling of 1061645581 in words is "one billion, sixty-one million, six hundred forty-five thousand, five hundred eighty-one".