81497461 has 4 divisors (see below), whose sum is σ = 81732672. Its totient is φ = 81262252.

The previous prime is 81497431. The next prime is 81497477. The reversal of 81497461 is 16479418.

It is the 3686-th star number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81497461 - 2¹³ = 81489269 is a prime.

It is a super-2 number, since 2×81497461² = 13283672298893042, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81497401) 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, 117085 + ... + 117778.

It is an arithmetic number, because the mean of its divisors is an integer number (20433168).

Almost surely, 2^81497461 is an apocalyptic number.

It is an amenable number.

81497461 is a deficient number, since it is larger than the sum of its proper divisors (235211).

81497461 is a wasteful number, since it uses less digits than its factorization.

81497461 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 235210.

The product of its digits is 48384, while the sum is 40.

The square root of 81497461 is about 9027.5944193345. The cubic root of 81497461 is about 433.5588206474.

The spelling of 81497461 in words is "eighty-one million, four hundred ninety-seven thousand, four hundred sixty-one".