81753945 has 64 divisors (see below), whose sum is σ = 162860544. Its totient is φ = 34099200.

The previous prime is 81753943. The next prime is 81753949. The reversal of 81753945 is 54935718.

It is not a de Polignac number, because 81753945 - 2¹ = 81753943 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 81753897 and 81753906.

It is not an unprimeable number, because it can be changed into a prime (81753943) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 137569 + ... + 138161.

It is an arithmetic number, because the mean of its divisors is an integer number (2544696).

Almost surely, 2^81753945 is an apocalyptic number.

It is an amenable number.

81753945 is a deficient number, since it is larger than the sum of its proper divisors (81106599).

81753945 is a wasteful number, since it uses less digits than its factorization.

81753945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 722.

The product of its digits is 151200, while the sum is 42.

The square root of 81753945 is about 9041.7888163792. The cubic root of 81753945 is about 434.0131679271.

The spelling of 81753945 in words is "eighty-one million, seven hundred fifty-three thousand, nine hundred forty-five".