71985000781 has 8 divisors (see below), whose sum is σ = 73398261600. Its totient is φ = 70578179280.

The previous prime is 71985000749. The next prime is 71985000793. The reversal of 71985000781 is 18700058917.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 71985000781 - 2⁵ = 71985000749 is a prime.

It is a super-2 number, since 2×71985000781² (a number of 23 digits) 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 (71985004781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1587250 + ... + 1631971.

It is an arithmetic number, because the mean of its divisors is an integer number (9174782700).

Almost surely, 2^71985000781 is an apocalyptic number.

71985000781 is the 119988-th centered decagonal number.

It is an amenable number.

71985000781 is a deficient number, since it is larger than the sum of its proper divisors (1413260819).

71985000781 is a wasteful number, since it uses less digits than its factorization.

71985000781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3219659.

The product of its (nonzero) digits is 141120, while the sum is 46.

The spelling of 71985000781 in words is "seventy-one billion, nine hundred eighty-five million, seven hundred eighty-one", and thus it is an aban number.