85780781 has 8 divisors (see below), whose sum is σ = 88594560. Its totient is φ = 83008288.

The previous prime is 85780771. The next prime is 85780819. The reversal of 85780781 is 18708758.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-85780781 is a prime.

It is a super-2 number, since 2×85780781² = 14716684777939922, 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 (85780771) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6071 + ... + 14436.

It is an arithmetic number, because the mean of its divisors is an integer number (11074320).

Almost surely, 2^85780781 is an apocalyptic number.

It is an amenable number.

85780781 is a deficient number, since it is larger than the sum of its proper divisors (2813779).

85780781 is a wasteful number, since it uses less digits than its factorization.

85780781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20643.

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

The square root of 85780781 is about 9261.7914573802. The cubic root of 85780781 is about 441.0251252733.

The spelling of 85780781 in words is "eighty-five million, seven hundred eighty thousand, seven hundred eighty-one".