81013541 has 4 divisors (see below), whose sum is σ = 92586912. Its totient is φ = 69440172.

The previous prime is 81013523. The next prime is 81013547. The reversal of 81013541 is 14531018.

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, and also an emirpimes, since its reverse is a distinct semiprime: 14531018 = 2 ⋅7265509.

It is a cyclic number.

It is not a de Polignac number, because 81013541 - 2¹⁸ = 80751397 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81013547) 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, 5786675 + ... + 5786688.

It is an arithmetic number, because the mean of its divisors is an integer number (23146728).

Almost surely, 2^81013541 is an apocalyptic number.

It is an amenable number.

81013541 is a deficient number, since it is larger than the sum of its proper divisors (11573371).

81013541 is a wasteful number, since it uses less digits than its factorization.

81013541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11573370.

The product of its (nonzero) digits is 480, while the sum is 23.

The square root of 81013541 is about 9000.7522463403. The cubic root of 81013541 is about 432.6989802444.

Adding to 81013541 its reverse (14531018), we get a palindrome (95544559).

The spelling of 81013541 in words is "eighty-one million, thirteen thousand, five hundred forty-one".