840468638 has 4 divisors (see below), whose sum is σ = 1260702960. Its totient is φ = 420234318.

The previous prime is 840468623. The next prime is 840468649. The reversal of 840468638 is 836864048.

It is a semiprime because it is the product of two primes.

It is a junction number, because it is equal to n+sod(n) for n = 840468592 and 840468601.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210117158 + ... + 210117161.

It is an arithmetic number, because the mean of its divisors is an integer number (315175740).

Almost surely, 2^840468638 is an apocalyptic number.

840468638 is a deficient number, since it is larger than the sum of its proper divisors (420234322).

840468638 is a wasteful number, since it uses less digits than its factorization.

840468638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 420234321.

The product of its (nonzero) digits is 884736, while the sum is 47.

The square root of 840468638 is about 28990.8371386547. The cubic root of 840468638 is about 943.7142309558.

The spelling of 840468638 in words is "eight hundred forty million, four hundred sixty-eight thousand, six hundred thirty-eight".