81041957 has 4 divisors (see below), whose sum is σ = 81063840. Its totient is φ = 81020076.

The previous prime is 81041911. The next prime is 81041963. The reversal of 81041957 is 75914018.

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: 75914018 = 2 ⋅37957009.

It is a cyclic number.

It is not a de Polignac number, because 81041957 - 2⁶ = 81041893 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 (81041557) 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, 3857 + ... + 13302.

It is an arithmetic number, because the mean of its divisors is an integer number (20265960).

Almost surely, 2^81041957 is an apocalyptic number.

It is an amenable number.

81041957 is a deficient number, since it is larger than the sum of its proper divisors (21883).

81041957 is a wasteful number, since it uses less digits than its factorization.

81041957 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21882.

The product of its (nonzero) digits is 10080, while the sum is 35.

The square root of 81041957 is about 9002.3306426725. The cubic root of 81041957 is about 432.7495649441.

The spelling of 81041957 in words is "eighty-one million, forty-one thousand, nine hundred fifty-seven".