61643800643 has 2 divisors, whose sum is σ = 61643800644. Its totient is φ = 61643800642.

The previous prime is 61643800601. The next prime is 61643800703. The reversal of 61643800643 is 34600834616.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 61643800643 - 2⁶ = 61643800579 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 61643800643.

It is not a weakly prime, because it can be changed into another prime (61643800943) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30821900321 + 30821900322.

It is an arithmetic number, because the mean of its divisors is an integer number (30821900322).

Almost surely, 2^61643800643 is an apocalyptic number.

61643800643 is a deficient number, since it is larger than the sum of its proper divisors (1).

61643800643 is an equidigital number, since it uses as much as digits as its factorization.

61643800643 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 248832, while the sum is 41.

The spelling of 61643800643 in words is "sixty-one billion, six hundred forty-three million, eight hundred thousand, six hundred forty-three".