61139109 has 4 divisors (see below), whose sum is σ = 81518816. Its totient is φ = 40759404.

The previous prime is 61139087. The next prime is 61139153. The reversal of 61139109 is 90193116.

61139109 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 not a de Polignac number, because 61139109 - 2¹² = 61135013 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 (61139009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10189849 + ... + 10189854.

It is an arithmetic number, because the mean of its divisors is an integer number (20379704).

Almost surely, 2^61139109 is an apocalyptic number.

It is an amenable number.

61139109 is a deficient number, since it is larger than the sum of its proper divisors (20379707).

61139109 is a wasteful number, since it uses less digits than its factorization.

61139109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20379706.

The product of its (nonzero) digits is 1458, while the sum is 30.

The square root of 61139109 is about 7819.1501456360. The cubic root of 61139109 is about 393.9487272986.

The spelling of 61139109 in words is "sixty-one million, one hundred thirty-nine thousand, one hundred nine".