1634989 has 8 divisors (see below), whose sum is σ = 1710720. Its totient is φ = 1561056.

The previous prime is 1634987. The next prime is 1635013. The reversal of 1634989 is 9894361.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1634989 - 2¹ = 1634987 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1634987) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1617 + ... + 2425.

It is an arithmetic number, because the mean of its divisors is an integer number (213840).

2^1634989 is an apocalyptic number.

1634989 is the 809-th heptagonal number.

It is an amenable number.

1634989 is a deficient number, since it is larger than the sum of its proper divisors (75731).

1634989 is an equidigital number, since it uses as much as digits as its factorization.

1634989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 899.

The product of its digits is 46656, while the sum is 40.

The square root of 1634989 is about 1278.6668839068. Note that the first 3 decimals coincide. The cubic root of 1634989 is about 117.8071397135.

The spelling of 1634989 in words is "one million, six hundred thirty-four thousand, nine hundred eighty-nine".