61309439 has 4 divisors (see below), whose sum is σ = 61409424. Its totient is φ = 61209456.

The previous prime is 61309433. The next prime is 61309471. The reversal of 61309439 is 93490316.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61309439 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 61309399 and 61309408.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61309433) 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, 49067 + ... + 50300.

It is an arithmetic number, because the mean of its divisors is an integer number (15352356).

Almost surely, 2^61309439 is an apocalyptic number.

61309439 is a deficient number, since it is larger than the sum of its proper divisors (99985).

61309439 is an equidigital number, since it uses as much as digits as its factorization.

61309439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99984.

The product of its (nonzero) digits is 17496, while the sum is 35.

The square root of 61309439 is about 7830.0344188260. The cubic root of 61309439 is about 394.3142274979.

The spelling of 61309439 in words is "sixty-one million, three hundred nine thousand, four hundred thirty-nine".