61643443 has 4 divisors (see below), whose sum is σ = 63309520. Its totient is φ = 59977368.

The previous prime is 61643423. The next prime is 61643471. The reversal of 61643443 is 34434616.

It is a happy number.

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-61643443 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61643423) 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, 832983 + ... + 833056.

It is an arithmetic number, because the mean of its divisors is an integer number (15827380).

Almost surely, 2^61643443 is an apocalyptic number.

61643443 is a deficient number, since it is larger than the sum of its proper divisors (1666077).

61643443 is a wasteful number, since it uses less digits than its factorization.

61643443 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1666076.

The product of its digits is 20736, while the sum is 31.

The square root of 61643443 is about 7851.3338357250. Note that the first 3 decimals coincide. The cubic root of 61643443 is about 395.0289846808.

The spelling of 61643443 in words is "sixty-one million, six hundred forty-three thousand, four hundred forty-three".