85157781 has 16 divisors (see below), whose sum is σ = 115473600. Its totient is φ = 55814528.

The previous prime is 85157771. The next prime is 85157783. The reversal of 85157781 is 18775158.

It is a cyclic number.

It is not a de Polignac number, because 85157781 - 2⁹ = 85157269 is a prime.

It is a super-2 number, since 2×85157781² = 14503695329687922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85157783) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 51790 + ... + 53408.

It is an arithmetic number, because the mean of its divisors is an integer number (7217100).

Almost surely, 2^85157781 is an apocalyptic number.

It is an amenable number.

85157781 is a deficient number, since it is larger than the sum of its proper divisors (30315819).

85157781 is a wasteful number, since it uses less digits than its factorization.

85157781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1908.

The product of its digits is 78400, while the sum is 42.

The square root of 85157781 is about 9228.0973661963. The cubic root of 85157781 is about 439.9548524613.

The spelling of 85157781 in words is "eighty-five million, one hundred fifty-seven thousand, seven hundred eighty-one".