1631988 has 72 divisors (see below), whose sum is σ = 4525248. Its totient is φ = 513216.

The previous prime is 1631969. The next prime is 1631989. The reversal of 1631988 is 8891361.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1631989) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 22320 + ... + 22392.

2^1631988 is an apocalyptic number.

1631988 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1631988, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2262624).

1631988 is an abundant number, since it is smaller than the sum of its proper divisors (2893260).

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

1631988 is a wasteful number, since it uses less digits than its factorization.

1631988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115 (or 101 counting only the distinct ones).

The product of its digits is 10368, while the sum is 36.

The square root of 1631988 is about 1277.4928571229. The cubic root of 1631988 is about 117.7350177700.

The spelling of 1631988 in words is "one million, six hundred thirty-one thousand, nine hundred eighty-eight".