71653 has 4 divisors (see below), whose sum is σ = 72640. Its totient is φ = 70668.

The previous prime is 71647. The next prime is 71663. The reversal of 71653 is 35617.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-71653 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 (71633) 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, 375 + ... + 532.

It is an arithmetic number, because the mean of its divisors is an integer number (18160).

2⁷¹⁶⁵³ is an apocalyptic number.

It is an amenable number.

71653 is a deficient number, since it is larger than the sum of its proper divisors (987).

71653 is an equidigital number, since it uses as much as digits as its factorization.

71653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 986.

The product of its digits is 630, while the sum is 22.

The square root of 71653 is about 267.6807800347. The cubic root of 71653 is about 41.5347364849.

Subtracting from 71653 its sum of digits (22), we obtain a triangular number (71631 = T₃₇₈).

The spelling of 71653 in words is "seventy-one thousand, six hundred fifty-three".