81955653 has 32 divisors (see below), whose sum is σ = 122653440. Its totient is φ = 48330240.

The previous prime is 81955637. The next prime is 81955663. The reversal of 81955653 is 35655918.

It is not a de Polignac number, because 81955653 - 2⁴ = 81955637 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81955663) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 263368 + ... + 263678.

It is an arithmetic number, because the mean of its divisors is an integer number (3832920).

Almost surely, 2^81955653 is an apocalyptic number.

It is an amenable number.

81955653 is a deficient number, since it is larger than the sum of its proper divisors (40697787).

81955653 is a wasteful number, since it uses less digits than its factorization.

81955653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 589.

The product of its digits is 162000, while the sum is 42.

The square root of 81955653 is about 9052.9361535360. The cubic root of 81955653 is about 434.3698154618.

The spelling of 81955653 in words is "eighty-one million, nine hundred fifty-five thousand, six hundred fifty-three".