67661649 has 48 divisors (see below), whose sum is σ = 117149760. Its totient is φ = 38568960.

The previous prime is 67661647. The next prime is 67661689. The reversal of 67661649 is 94616676.

It is a happy number.

It is not a de Polignac number, because 67661649 - 2¹ = 67661647 is a prime.

It is not an unprimeable number, because it can be changed into a prime (67661647) 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 47 ways as a sum of consecutive naturals, for example, 44697 + ... + 46185.

It is an arithmetic number, because the mean of its divisors is an integer number (2440620).

Almost surely, 2^67661649 is an apocalyptic number.

It is an amenable number.

67661649 is a deficient number, since it is larger than the sum of its proper divisors (49488111).

67661649 is a wasteful number, since it uses less digits than its factorization.

67661649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1532 (or 1520 counting only the distinct ones).

The product of its digits is 326592, while the sum is 45.

The square root of 67661649 is about 8225.6701246768. The cubic root of 67661649 is about 407.4874077432.

It can be divided in two parts, 6 and 7661649, that added together give a triangular number (7661655 = T₃₉₁₄).

The spelling of 67661649 in words is "sixty-seven million, six hundred sixty-one thousand, six hundred forty-nine".