71640646 has 24 divisors (see below), whose sum is σ = 136371816. Its totient is φ = 27911520.

The previous prime is 71640637. The next prime is 71640649. The reversal of 71640646 is 64604617.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71640649) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 32151 + ... + 34306.

It is an arithmetic number, because the mean of its divisors is an integer number (5682159).

Almost surely, 2^71640646 is an apocalyptic number.

71640646 is a deficient number, since it is larger than the sum of its proper divisors (64731170).

71640646 is a wasteful number, since it uses less digits than its factorization.

71640646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66484 (or 66477 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 34.

The square root of 71640646 is about 8464.0797491517. The cubic root of 71640646 is about 415.3234928724.

The spelling of 71640646 in words is "seventy-one million, six hundred forty thousand, six hundred forty-six".