856973661 has 8 divisors (see below), whose sum is σ = 1143170880. Its totient is φ = 571046112.

The previous prime is 856973657. The next prime is 856973669. The reversal of 856973661 is 166379658.

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

It is not a de Polignac number, because 856973661 - 2² = 856973657 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (856973669) 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, 59881 + ... + 72798.

It is an arithmetic number, because the mean of its divisors is an integer number (142896360).

Almost surely, 2^856973661 is an apocalyptic number.

It is an amenable number.

856973661 is a deficient number, since it is larger than the sum of its proper divisors (286197219).

856973661 is a wasteful number, since it uses less digits than its factorization.

856973661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134835.

The product of its digits is 1632960, while the sum is 51.

The square root of 856973661 is about 29274.1124716019. The cubic root of 856973661 is about 949.8517445471.

The spelling of 856973661 in words is "eight hundred fifty-six million, nine hundred seventy-three thousand, six hundred sixty-one".