840634 has 4 divisors (see below), whose sum is σ = 1260954. Its totient is φ = 420316.

The previous prime is 840611. The next prime is 840643. The reversal of 840634 is 436048.

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

It can be written as a sum of positive squares in only one way, i.e., 819025 + 21609 = 905^2 + 147^2 .

It is a junction number, because it is equal to n+sod(n) for n = 840599 and 840608.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210157 + ... + 210160.

2⁸⁴⁰⁶³⁴ is an apocalyptic number.

840634 is a deficient number, since it is larger than the sum of its proper divisors (420320).

840634 is a wasteful number, since it uses less digits than its factorization.

840634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 420319.

The product of its (nonzero) digits is 2304, while the sum is 25.

The square root of 840634 is about 916.8609491084. The cubic root of 840634 is about 94.3776118746.

The spelling of 840634 in words is "eight hundred forty thousand, six hundred thirty-four".