71643840 has 112 divisors (see below), whose sum is σ = 233732832. Its totient is φ = 18579456.

The previous prime is 71643809. The next prime is 71643853. The reversal of 71643840 is 4834617.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 34512 + ... + 36528.

Almost surely, 2^71643840 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 71643840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (116866416).

71643840 is an abundant number, since it is smaller than the sum of its proper divisors (162088992).

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

71643840 is a wasteful number, since it uses less digits than its factorization.

71643840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2074 (or 2064 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 33.

The square root of 71643840 is about 8464.2684267455. The cubic root of 71643840 is about 415.3296649902.

The spelling of 71643840 in words is "seventy-one million, six hundred forty-three thousand, eight hundred forty".