71287780 has 12 divisors (see below), whose sum is σ = 149704380. Its totient is φ = 28515104.

The previous prime is 71287759. The next prime is 71287793. The reversal of 71287780 is 8778217.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 45724644 + 25563136 = 6762^2 + 5056^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1782175 + ... + 1782214.

It is an arithmetic number, because the mean of its divisors is an integer number (12475365).

Almost surely, 2^71287780 is an apocalyptic number.

It is an amenable number.

71287780 is an abundant number, since it is smaller than the sum of its proper divisors (78416600).

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

71287780 is a wasteful number, since it uses less digits than its factorization.

71287780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3564398 (or 3564396 counting only the distinct ones).

The product of its (nonzero) digits is 43904, while the sum is 40.

The square root of 71287780 is about 8443.2091055475. The cubic root of 71287780 is about 414.6404782947.

The spelling of 71287780 in words is "seventy-one million, two hundred eighty-seven thousand, seven hundred eighty".