61812643 has 4 divisors (see below), whose sum is σ = 65065960. Its totient is φ = 58559328.

The previous prime is 61812623. The next prime is 61812679. The reversal of 61812643 is 34621816.

It is a happy number.

61812643 is nontrivially palindromic in base 16.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61812643 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61812613) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1626630 + ... + 1626667.

It is an arithmetic number, because the mean of its divisors is an integer number (16266490).

Almost surely, 2^61812643 is an apocalyptic number.

61812643 is a deficient number, since it is larger than the sum of its proper divisors (3253317).

61812643 is a wasteful number, since it uses less digits than its factorization.

61812643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3253316.

The product of its digits is 6912, while the sum is 31.

The square root of 61812643 is about 7862.1016910238. The cubic root of 61812643 is about 395.3900819876.

The spelling of 61812643 in words is "sixty-one million, eight hundred twelve thousand, six hundred forty-three".