61781943 has 8 divisors (see below), whose sum is σ = 82455408. Its totient is φ = 41148224.

The previous prime is 61781917. The next prime is 61781953. The reversal of 61781943 is 34918716.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 61781943 - 2⁶ = 61781879 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61781903) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6096 + ... + 12677.

It is an arithmetic number, because the mean of its divisors is an integer number (10306926).

Almost surely, 2^61781943 is an apocalyptic number.

61781943 is a deficient number, since it is larger than the sum of its proper divisors (20673465).

61781943 is a wasteful number, since it uses less digits than its factorization.

61781943 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19873.

The product of its digits is 36288, while the sum is 39.

The square root of 61781943 is about 7860.1490443884. The cubic root of 61781943 is about 395.3246127187.

The spelling of 61781943 in words is "sixty-one million, seven hundred eighty-one thousand, nine hundred forty-three".