634890 has 16 divisors (see below), whose sum is σ = 1523808. Its totient is φ = 169296.

The previous prime is 634871. The next prime is 634891. The reversal of 634890 is 98436.

It is a Harshad number since it is a multiple of its sum of digits (30), and also a Moran number because the ratio is a prime number: 21163 = 634890 / (6 + 3 + 4 + 8 + 9 + 0).

It is not an unprimeable number, because it can be changed into a prime (634891) by changing a digit.

634890 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10552 + ... + 10611.

It is an arithmetic number, because the mean of its divisors is an integer number (95238).

2⁶³⁴⁸⁹⁰ is an apocalyptic number.

634890 is an abundant number, since it is smaller than the sum of its proper divisors (888918).

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

634890 is a wasteful number, since it uses less digits than its factorization.

634890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21173.

The product of its (nonzero) digits is 5184, while the sum is 30.

The square root of 634890 is about 796.7998493976. The cubic root of 634890 is about 85.9474169272.

The spelling of 634890 in words is "six hundred thirty-four thousand, eight hundred ninety".