61081009 has 4 divisors (see below), whose sum is σ = 66633840. Its totient is φ = 55528180.

The previous prime is 61081003. The next prime is 61081037. The reversal of 61081009 is 90018016.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 61081009 - 2¹⁹ = 60556721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61081003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2776399 + ... + 2776420.

It is an arithmetic number, because the mean of its divisors is an integer number (16658460).

Almost surely, 2^61081009 is an apocalyptic number.

It is an amenable number.

61081009 is a deficient number, since it is larger than the sum of its proper divisors (5552831).

61081009 is a wasteful number, since it uses less digits than its factorization.

61081009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5552830.

The product of its (nonzero) digits is 432, while the sum is 25.

The square root of 61081009 is about 7815.4340250558. The cubic root of 61081009 is about 393.8238989878.

It can be divided in two parts, 6108 and 1009, that added together give a palindrome (7117).

The spelling of 61081009 in words is "sixty-one million, eighty-one thousand, nine".