857156661 has 40 divisors (see below), whose sum is σ = 1322075040. Its totient is φ = 553161312.

The previous prime is 857156639. The next prime is 857156723. The reversal of 857156661 is 166651758.

857156661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 857156661 - 2⁷ = 857156533 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (857156561) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 318855 + ... + 321531.

It is an arithmetic number, because the mean of its divisors is an integer number (33051876).

Almost surely, 2^857156661 is an apocalyptic number.

857156661 is a gapful number since it is divisible by the number (81) formed by its first and last digit.

It is an amenable number.

857156661 is a deficient number, since it is larger than the sum of its proper divisors (464918379).

857156661 is a wasteful number, since it uses less digits than its factorization.

857156661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2815 (or 2806 counting only the distinct ones).

The product of its digits is 302400, while the sum is 45.

The square root of 857156661 is about 29277.2379332477. The cubic root of 857156661 is about 949.9193508636.

The spelling of 857156661 in words is "eight hundred fifty-seven million, one hundred fifty-six thousand, six hundred sixty-one".