71651 has 4 divisors (see below), whose sum is σ = 72312. Its totient is φ = 70992.

The previous prime is 71647. The next prime is 71663. The reversal of 71651 is 15617.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 71651 - 2² = 71647 is a prime.

It is a Duffinian number.

It is a plaindrome in base 12.

It is not an unprimeable number, because it can be changed into a prime (71671) 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, 125 + ... + 398.

It is an arithmetic number, because the mean of its divisors is an integer number (18078).

2⁷¹⁶⁵¹ is an apocalyptic number.

71651 is a deficient number, since it is larger than the sum of its proper divisors (661).

71651 is a wasteful number, since it uses less digits than its factorization.

71651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 660.

The product of its digits is 210, while the sum is 20.

The square root of 71651 is about 267.6770442156. The cubic root of 71651 is about 41.5343500380.

Subtracting from 71651 its sum of digits (20), we obtain a triangular number (71631 = T₃₇₈).

It can be divided in two parts, 716 and 51, that added together give a palindrome (767).

The spelling of 71651 in words is "seventy-one thousand, six hundred fifty-one".