61644143 has 4 divisors (see below), whose sum is σ = 67248168. Its totient is φ = 56040120.

The previous prime is 61644139. The next prime is 61644157. The reversal of 61644143 is 34144616.

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 61644143 - 2² = 61644139 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61644133) 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, 2801996 + ... + 2802017.

It is an arithmetic number, because the mean of its divisors is an integer number (16812042).

Almost surely, 2^61644143 is an apocalyptic number.

61644143 is a deficient number, since it is larger than the sum of its proper divisors (5604025).

61644143 is a wasteful number, since it uses less digits than its factorization.

61644143 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5604024.

The product of its digits is 6912, while the sum is 29.

The square root of 61644143 is about 7851.3784140111. The cubic root of 61644143 is about 395.0304799425.

Adding to 61644143 its reverse (34144616), we get a palindrome (95788759).

The spelling of 61644143 in words is "sixty-one million, six hundred forty-four thousand, one hundred forty-three".