81000461 has 16 divisors (see below), whose sum is σ = 88397568. Its totient is φ = 73920000.

The previous prime is 81000449. The next prime is 81000463. The reversal of 81000461 is 16400018.

It is a cyclic number.

It is not a de Polignac number, because 81000461 - 2¹⁰ = 80999437 is a prime.

It is a super-2 number, since 2×81000461² = 13122149364425042, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81000463) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 174716 + ... + 175178.

It is an arithmetic number, because the mean of its divisors is an integer number (5524848).

Almost surely, 2^81000461 is an apocalyptic number.

It is an amenable number.

81000461 is a deficient number, since it is larger than the sum of its proper divisors (7397107).

81000461 is a wasteful number, since it uses less digits than its factorization.

81000461 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 772.

The product of its (nonzero) digits is 192, while the sum is 20.

The square root of 81000461 is about 9000.0256110747. The cubic root of 81000461 is about 432.6756919265.

Adding to 81000461 its reverse (16400018), we get a palindrome (97400479).

The spelling of 81000461 in words is "eighty-one million, four hundred sixty-one", and thus it is an aban number.