857222661 has 16 divisors (see below), whose sum is σ = 1148516928. Its totient is φ = 568713600.

The previous prime is 857222609. The next prime is 857222683. The reversal of 857222661 is 166222758.

It is not a de Polignac number, because 857222661 - 2¹⁰ = 857221637 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (857229661) 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, 766875 + ... + 767991.

It is an arithmetic number, because the mean of its divisors is an integer number (71782308).

Almost surely, 2^857222661 is an apocalyptic number.

It is an amenable number.

857222661 is a deficient number, since it is larger than the sum of its proper divisors (291294267).

857222661 is a wasteful number, since it uses less digits than its factorization.

857222661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2132.

The product of its digits is 80640, while the sum is 39.

The square root of 857222661 is about 29278.3650670593. The cubic root of 857222661 is about 949.9437311086.

The spelling of 857222661 in words is "eight hundred fifty-seven million, two hundred twenty-two thousand, six hundred sixty-one".