840385251 has 6 divisors (see below), whose sum is σ = 1213889820. Its totient is φ = 560256828.

The previous prime is 840385223. The next prime is 840385253. The reversal of 840385251 is 152583048.

It is a happy number.

It is not a de Polignac number, because 840385251 - 2²⁷ = 706167523 is a prime.

It is not an unprimeable number, because it can be changed into a prime (840385253) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 46688061 + ... + 46688078.

It is an arithmetic number, because the mean of its divisors is an integer number (202314970).

Almost surely, 2^840385251 is an apocalyptic number.

840385251 is a deficient number, since it is larger than the sum of its proper divisors (373504569).

840385251 is a wasteful number, since it uses less digits than its factorization.

840385251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93376145 (or 93376142 counting only the distinct ones).

The product of its (nonzero) digits is 38400, while the sum is 36.

The square root of 840385251 is about 28989.3989416821. The cubic root of 840385251 is about 943.6830197570.

The spelling of 840385251 in words is "eight hundred forty million, three hundred eighty-five thousand, two hundred fifty-one".