61439661 has 16 divisors (see below), whose sum is σ = 94161600. Its totient is φ = 39546864.

The previous prime is 61439659. The next prime is 61439681. The reversal of 61439661 is 16693416.

61439661 is a `hidden beast` number, since 614 + 39 + 6 + 6 + 1 = 666.

It is not a de Polignac number, because 61439661 - 2¹ = 61439659 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61439611) 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 15 ways as a sum of consecutive naturals, for example, 38451 + ... + 40016.

It is an arithmetic number, because the mean of its divisors is an integer number (5885100).

Almost surely, 2^61439661 is an apocalyptic number.

It is an amenable number.

61439661 is a deficient number, since it is larger than the sum of its proper divisors (32721939).

61439661 is a wasteful number, since it uses less digits than its factorization.

61439661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78505 (or 78499 counting only the distinct ones).

The product of its digits is 23328, while the sum is 36.

The square root of 61439661 is about 7838.3455524747. The cubic root of 61439661 is about 394.5932061573.

The spelling of 61439661 in words is "sixty-one million, four hundred thirty-nine thousand, six hundred sixty-one".