74218649761 has 15 divisors (see below), whose sum is σ = 76665522021. Its totient is φ = 71849862216.

The previous prime is 74218649719. The next prime is 74218649801. The reversal of 74218649761 is 16794681247.

The square root of 74218649761 is 272431.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 2 ways, for example, as 46276184161 + 27942465600 = 215119^2 + 167160^2 .

It is not a de Polignac number, because 74218649761 - 2¹⁹ = 74218125473 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (74218643761) 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 14 ways as a sum of consecutive naturals, for example, 372957940 + ... + 372958138.

Almost surely, 2^74218649761 is an apocalyptic number.

74218649761 is the 272431-st square number.

74218649761 is the 136216-th centered octagonal number.

It is an amenable number.

74218649761 is a deficient number, since it is larger than the sum of its proper divisors (2446872260).

74218649761 is an frugal number, since it uses more digits than its factorization.

74218649761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 546 (or 236 counting only the distinct ones).

The product of its digits is 4064256, while the sum is 55.

The spelling of 74218649761 in words is "seventy-four billion, two hundred eighteen million, six hundred forty-nine thousand, seven hundred sixty-one".