71837640 has 192 divisors, whose sum is σ = 276307200. Its totient is φ = 15837696.

The previous prime is 71837599. The next prime is 71837641. The reversal of 71837640 is 4673817.

71837640 is a `hidden beast` number, since 7 + 1 + 8 + 3 + 7 + 640 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 71837595 and 71837604.

It is not an unprimeable number, because it can be changed into a prime (71837641) 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, 72589 + ... + 73571.

It is an arithmetic number, because the mean of its divisors is an integer number (1439100).

Almost surely, 2^71837640 is an apocalyptic number.

71837640 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 71837640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (138153600).

71837640 is an abundant number, since it is smaller than the sum of its proper divisors (204469560).

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

71837640 is a wasteful number, since it uses less digits than its factorization.

71837640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1036 (or 1029 counting only the distinct ones).

The product of its (nonzero) digits is 28224, while the sum is 36.

The square root of 71837640 is about 8475.7088199159. The cubic root of 71837640 is about 415.7038233301.

The spelling of 71837640 in words is "seventy-one million, eight hundred thirty-seven thousand, six hundred forty".