71978436 has 24 divisors (see below), whose sum is σ = 186611040. Its totient is φ = 23992776.

The previous prime is 71978429. The next prime is 71978437. The reversal of 71978436 is 63487917.

It is a junction number, because it is equal to n+sod(n) for n = 71978391 and 71978400.

It is not an unprimeable number, because it can be changed into a prime (71978437) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 333126 + ... + 333341.

It is an arithmetic number, because the mean of its divisors is an integer number (7775460).

Almost surely, 2^71978436 is an apocalyptic number.

It is an amenable number.

71978436 is an abundant number, since it is smaller than the sum of its proper divisors (114632604).

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

71978436 is a wasteful number, since it uses less digits than its factorization.

71978436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 666480 (or 666472 counting only the distinct ones).

The product of its digits is 254016, while the sum is 45.

The square root of 71978436 is about 8484.0106081970. The cubic root of 71978436 is about 415.9752281230.

The spelling of 71978436 in words is "seventy-one million, nine hundred seventy-eight thousand, four hundred thirty-six".