71731530 has 96 divisors (see below), whose sum is σ = 206401104. Its totient is φ = 17169408.

The previous prime is 71731523. The next prime is 71731531. The reversal of 71731530 is 3513717.

It can be written as a sum of positive squares in 8 ways, for example, as 26532801 + 45198729 = 5151^2 + 6723^2 .

It is a super-2 number, since 2×71731530² = 10290824792281800, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 71731494 and 71731503.

It is not an unprimeable number, because it can be changed into a prime (71731531) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 42462 + ... + 44118.

Almost surely, 2^71731530 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 71731530, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103200552).

71731530 is an abundant number, since it is smaller than the sum of its proper divisors (134669574).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

71731530 is a wasteful number, since it uses less digits than its factorization.

71731530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1720 (or 1717 counting only the distinct ones).

The product of its (nonzero) digits is 2205, while the sum is 27.

The square root of 71731530 is about 8469.4468532484. The cubic root of 71731530 is about 415.4990464253.

The spelling of 71731530 in words is "seventy-one million, seven hundred thirty-one thousand, five hundred thirty".