71840640 has 256 divisors, whose sum is σ = 253808640. Its totient is φ = 17203200.

The previous prime is 71840633. The next prime is 71840641. The reversal of 71840640 is 4604817.

It is a super-2 number, since 2×71840640² = 10322155111219200, which contains 22 as substring.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 71840598 and 71840607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71840641) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1011805 + ... + 1011875.

It is an arithmetic number, because the mean of its divisors is an integer number (991440).

Almost surely, 2^71840640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 71840640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (126904320).

71840640 is an abundant number, since it is smaller than the sum of its proper divisors (181968000).

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

71840640 is a wasteful number, since it uses less digits than its factorization.

71840640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 141 (or 129 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 30.

The square root of 71840640 is about 8475.8857944170. The cubic root of 71840640 is about 415.7096099628.

The spelling of 71840640 in words is "seventy-one million, eight hundred forty thousand, six hundred forty".