81953541 has 6 divisors (see below), whose sum is σ = 118377350. Its totient is φ = 54635688.

The previous prime is 81953533. The next prime is 81953551. The reversal of 81953541 is 14535918.

81953541 is a `hidden beast` number, since 81 + 9 + 535 + 41 = 666.

It can be written as a sum of positive squares in only one way, i.e., 49702500 + 32251041 = 7050^2 + 5679^2 .

It is not a de Polignac number, because 81953541 - 2³ = 81953533 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 81953496 and 81953505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81953551) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4552966 + ... + 4552983.

Almost surely, 2^81953541 is an apocalyptic number.

It is an amenable number.

81953541 is a deficient number, since it is larger than the sum of its proper divisors (36423809).

81953541 is a wasteful number, since it uses less digits than its factorization.

81953541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9105955 (or 9105952 counting only the distinct ones).

The product of its digits is 21600, while the sum is 36.

The square root of 81953541 is about 9052.8195055463. The cubic root of 81953541 is about 434.3660841881.

The spelling of 81953541 in words is "eighty-one million, nine hundred fifty-three thousand, five hundred forty-one".