61309649 has 4 divisors (see below), whose sum is σ = 61366836. Its totient is φ = 61252464.

The previous prime is 61309621. The next prime is 61309687. The reversal of 61309649 is 94690316.

61309649 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.

It can be written as a sum of positive squares in 2 ways, for example, as 41667025 + 19642624 = 6455^2 + 4432^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61309649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61309049) 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, 26954 + ... + 29139.

It is an arithmetic number, because the mean of its divisors is an integer number (15341709).

Almost surely, 2^61309649 is an apocalyptic number.

It is an amenable number.

61309649 is a deficient number, since it is larger than the sum of its proper divisors (57187).

61309649 is a wasteful number, since it uses less digits than its factorization.

61309649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57186.

The product of its (nonzero) digits is 34992, while the sum is 38.

The square root of 61309649 is about 7830.0478287173. The cubic root of 61309649 is about 394.3146777053.

The spelling of 61309649 in words is "sixty-one million, three hundred nine thousand, six hundred forty-nine".