1631664 has 50 divisors (see below), whose sum is σ = 4726260. Its totient is φ = 543456.

The previous prime is 1631659. The next prime is 1631683. The reversal of 1631664 is 4661361.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 667 + ... + 1925.

2^1631664 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1631664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2363130).

1631664 is an abundant number, since it is smaller than the sum of its proper divisors (3094596).

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

1631664 is a wasteful number, since it uses less digits than its factorization.

1631664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1279 (or 1264 counting only the distinct ones).

The product of its digits is 2592, while the sum is 27.

The square root of 1631664 is about 1277.3660399431. The cubic root of 1631664 is about 117.7272259091.

The spelling of 1631664 in words is "one million, six hundred thirty-one thousand, six hundred sixty-four".