80587781 has 6 divisors (see below), whose sum is σ = 83416710. Its totient is φ = 77762216.

The previous prime is 80587777. The next prime is 80587811. The reversal of 80587781 is 18778508.

It can be written as a sum of positive squares in only one way, i.e., 69472225 + 11115556 = 8335^2 + 3334^2 .

It is not a de Polignac number, because 80587781 - 2² = 80587777 is a prime.

It is a super-2 number, since 2×80587781² = 12988780893007922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (80587711) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 47510 + ... + 49176.

It is an arithmetic number, because the mean of its divisors is an integer number (13902785).

Almost surely, 2^80587781 is an apocalyptic number.

It is an amenable number.

80587781 is a deficient number, since it is larger than the sum of its proper divisors (2828929).

80587781 is an frugal number, since it uses more digits than its factorization.

80587781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3363 (or 1696 counting only the distinct ones).

The product of its (nonzero) digits is 125440, while the sum is 44.

The square root of 80587781 is about 8977.0697334932. The cubic root of 80587781 is about 431.9396438455.

The spelling of 80587781 in words is "eighty million, five hundred eighty-seven thousand, seven hundred eighty-one".