71172640 has 192 divisors, whose sum is σ = 215550720. Its totient is φ = 21565440.

The previous prime is 71172637. The next prime is 71172671. The reversal of 71172640 is 4627117.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a junction number, because it is equal to n+sod(n) for n = 71172599 and 71172608.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 652906 + ... + 653014.

It is an arithmetic number, because the mean of its divisors is an integer number (1122660).

Almost surely, 2^71172640 is an apocalyptic number.

71172640 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 71172640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (107775360).

71172640 is an abundant number, since it is smaller than the sum of its proper divisors (144378080).

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

71172640 is a wasteful number, since it uses less digits than its factorization.

71172640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 195 (or 187 counting only the distinct ones).

The product of its (nonzero) digits is 2352, while the sum is 28.

The square root of 71172640 is about 8436.3878526298. The cubic root of 71172640 is about 414.4171233663.

Adding to 71172640 its reverse (4627117), we get a palindrome (75799757).

The spelling of 71172640 in words is "seventy-one million, one hundred seventy-two thousand, six hundred forty".