5645420681 has 2 divisors, whose sum is σ = 5645420682. Its totient is φ = 5645420680.

The previous prime is 5645420653. The next prime is 5645420699. The reversal of 5645420681 is 1860245465.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4024633600 + 1620787081 = 63440^2 + 40259^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-5645420681 is a prime.

It is a super-2 number, since 2×5645420681² = 63741549330925007522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (5645428681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2822710340 + 2822710341.

It is an arithmetic number, because the mean of its divisors is an integer number (2822710341).

Almost surely, 2^5645420681 is an apocalyptic number.

It is an amenable number.

5645420681 is a deficient number, since it is larger than the sum of its proper divisors (1).

5645420681 is an equidigital number, since it uses as much as digits as its factorization.

5645420681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 230400, while the sum is 41.

The square root of 5645420681 is about 75136.0145402988. The cubic root of 5645420681 is about 1780.5961771248.

It can be divided in two parts, 564 and 5420681, that added together give a palindrome (5421245).

The spelling of 5645420681 in words is "five billion, six hundred forty-five million, four hundred twenty thousand, six hundred eighty-one".