81653143 has 8 divisors (see below), whose sum is σ = 95928336. Its totient is φ = 68520000.

The previous prime is 81653129. The next prime is 81653149. The reversal of 81653143 is 34135618.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81653143 - 2¹⁷ = 81522071 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 (81653149) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 285358 + ... + 285643.

It is an arithmetic number, because the mean of its divisors is an integer number (11991042).

Almost surely, 2^81653143 is an apocalyptic number.

81653143 is a deficient number, since it is larger than the sum of its proper divisors (14275193).

81653143 is a wasteful number, since it uses less digits than its factorization.

81653143 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 571025.

The product of its digits is 8640, while the sum is 31.

The square root of 81653143 is about 9036.2128682319. The cubic root of 81653143 is about 433.8347162386.

It can be divided in two parts, 81653 and 143, that added together give a square (81796 = 286²).

The spelling of 81653143 in words is "eighty-one million, six hundred fifty-three thousand, one hundred forty-three".