645868961461 has 2 divisors, whose sum is σ = 645868961462. Its totient is φ = 645868961460.

The previous prime is 645868961429. The next prime is 645868961537. The reversal of 645868961461 is 164169868546.

645868961461 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 645441919236 + 427042225 = 803394^2 + 20665^2 .

It is a cyclic number.

It is not a de Polignac number, because 645868961461 - 2⁵ = 645868961429 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 645868961393 and 645868961402.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645868961261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322934480730 + 322934480731.

It is an arithmetic number, because the mean of its divisors is an integer number (322934480731).

Almost surely, 2^645868961461 is an apocalyptic number.

It is an amenable number.

645868961461 is a deficient number, since it is larger than the sum of its proper divisors (1).

645868961461 is an equidigital number, since it uses as much as digits as its factorization.

645868961461 is an evil number, because the sum of its binary digits is even.

The product of its digits is 59719680, while the sum is 64.

The spelling of 645868961461 in words is "six hundred forty-five billion, eight hundred sixty-eight million, nine hundred sixty-one thousand, four hundred sixty-one".