856439910 has 24 divisors (see below), whose sum is σ = 2226744000. Its totient is φ = 228383952.

The previous prime is 856439897. The next prime is 856439917. The reversal of 856439910 is 19934658.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (856439917) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4757910 + ... + 4758089.

It is an arithmetic number, because the mean of its divisors is an integer number (92781000).

Almost surely, 2^856439910 is an apocalyptic number.

856439910 is an abundant number, since it is smaller than the sum of its proper divisors (1370304090).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

856439910 is a wasteful number, since it uses less digits than its factorization.

856439910 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9516012 (or 9516009 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 45.

The square root of 856439910 is about 29264.9946181440. The cubic root of 856439910 is about 949.6545040975.

The spelling of 856439910 in words is "eight hundred fifty-six million, four hundred thirty-nine thousand, nine hundred ten".