856221242 has 4 divisors (see below), whose sum is σ = 1284331866. Its totient is φ = 428110620.

The previous prime is 856221241. The next prime is 856221313. The reversal of 856221242 is 242122658.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 242122658 = 2 ⋅121061329.

It can be written as a sum of positive squares in only one way, i.e., 711235561 + 144985681 = 26669^2 + 12041^2 .

It is a super-2 number, since 2×856221242² = 1466229630504045128, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 856221199 and 856221208.

It is not an unprimeable number, because it can be changed into a prime (856221241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 214055309 + ... + 214055312.

Almost surely, 2^856221242 is an apocalyptic number.

856221242 is a deficient number, since it is larger than the sum of its proper divisors (428110624).

856221242 is a wasteful number, since it uses less digits than its factorization.

856221242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 428110623.

The product of its digits is 15360, while the sum is 32.

The square root of 856221242 is about 29261.2583803226. The cubic root of 856221242 is about 949.5736746373.

The spelling of 856221242 in words is "eight hundred fifty-six million, two hundred twenty-one thousand, two hundred forty-two".