61781611 has 8 divisors (see below), whose sum is σ = 64546560. Its totient is φ = 59023272.

The previous prime is 61781609. The next prime is 61781617. The reversal of 61781611 is 11618716.

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 61781611 - 2¹ = 61781609 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61781617) 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 7 ways as a sum of consecutive naturals, for example, 34996 + ... + 36718.

It is an arithmetic number, because the mean of its divisors is an integer number (8068320).

Almost surely, 2^61781611 is an apocalyptic number.

61781611 is a deficient number, since it is larger than the sum of its proper divisors (2764949).

61781611 is a wasteful number, since it uses less digits than its factorization.

61781611 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3305.

The product of its digits is 2016, while the sum is 31.

The square root of 61781611 is about 7860.1279251676. The cubic root of 61781611 is about 395.3239045937.

It can be divided in two parts, 617816 and 11, that multiplied together give a palindrome (6795976).

The spelling of 61781611 in words is "sixty-one million, seven hundred eighty-one thousand, six hundred eleven".