73631681 has 4 divisors (see below), whose sum is σ = 75021012. Its totient is φ = 72242352.

The previous prime is 73631659. The next prime is 73631683. The reversal of 73631681 is 18613637.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18613637 = 7 ⋅2659091.

It can be written as a sum of positive squares in 2 ways, for example, as 46799281 + 26832400 = 6841^2 + 5180^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-73631681 is a prime.

It is a super-2 number, since 2×73631681² = 10843248893771522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (73631683) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 694586 + ... + 694691.

It is an arithmetic number, because the mean of its divisors is an integer number (18755253).

Almost surely, 2^73631681 is an apocalyptic number.

It is an amenable number.

73631681 is a deficient number, since it is larger than the sum of its proper divisors (1389331).

73631681 is a wasteful number, since it uses less digits than its factorization.

73631681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1389330.

The product of its digits is 18144, while the sum is 35.

The square root of 73631681 is about 8580.8904549586. The cubic root of 73631681 is about 419.1359428111.

The spelling of 73631681 in words is "seventy-three million, six hundred thirty-one thousand, six hundred eighty-one".