71778338920 has 32 divisors (see below), whose sum is σ = 163775934720. Its totient is φ = 28306949440.

The previous prime is 71778338899. The next prime is 71778338963. The reversal of 71778338920 is 2983387717.

It is a happy number.

It is a super-2 number, since 2×71778338920² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12634192 + ... + 12639871.

It is an arithmetic number, because the mean of its divisors is an integer number (5117997960).

Almost surely, 2^71778338920 is an apocalyptic number.

It is an amenable number.

71778338920 is an abundant number, since it is smaller than the sum of its proper divisors (91997595800).

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

71778338920 is a wasteful number, since it uses less digits than its factorization.

71778338920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25274145 (or 25274141 counting only the distinct ones).

The product of its (nonzero) digits is 3556224, while the sum is 55.

The spelling of 71778338920 in words is "seventy-one billion, seven hundred seventy-eight million, three hundred thirty-eight thousand, nine hundred twenty".