851491386 has 64 divisors (see below), whose sum is σ = 1950220800. Its totient is φ = 275240448.

The previous prime is 851491373. The next prime is 851491411. The reversal of 851491386 is 683194158.

851491386 is a `hidden beast` number, since 85 + 1 + 491 + 3 + 86 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 285310 + ... + 288278.

It is an arithmetic number, because the mean of its divisors is an integer number (30472200).

Almost surely, 2^851491386 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 851491386, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (975110400).

851491386 is an abundant number, since it is smaller than the sum of its proper divisors (1098729414).

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

851491386 is a wasteful number, since it uses less digits than its factorization.

851491386 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3140 (or 3134 counting only the distinct ones).

The product of its digits is 207360, while the sum is 45.

The square root of 851491386 is about 29180.3253237520. The cubic root of 851491386 is about 947.8219301816.

The spelling of 851491386 in words is "eight hundred fifty-one million, four hundred ninety-one thousand, three hundred eighty-six".