61810535643 has 4 divisors (see below), whose sum is σ = 82414047528. Its totient is φ = 41207023760.

The previous prime is 61810535587. The next prime is 61810535663. The reversal of 61810535643 is 34653501816.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 61810535643 - 2¹⁷ = 61810404571 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 61810535595 and 61810535604.

It is not an unprimeable number, because it can be changed into a prime (61810535663) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10301755938 + ... + 10301755943.

It is an arithmetic number, because the mean of its divisors is an integer number (20603511882).

Almost surely, 2^61810535643 is an apocalyptic number.

61810535643 is a deficient number, since it is larger than the sum of its proper divisors (20603511885).

61810535643 is a wasteful number, since it uses less digits than its factorization.

61810535643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20603511884.

The product of its (nonzero) digits is 259200, while the sum is 42.

The spelling of 61810535643 in words is "sixty-one billion, eight hundred ten million, five hundred thirty-five thousand, six hundred forty-three".