1981630 has 16 divisors (see below), whose sum is σ = 4076640. Its totient is φ = 679392.

The previous prime is 1981627. The next prime is 1981631. The reversal of 1981630 is 361891.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1981631) 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, 14085 + ... + 14224.

It is an arithmetic number, because the mean of its divisors is an integer number (254790).

2^1981630 is an apocalyptic number.

1981630 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1981630 is an abundant number, since it is smaller than the sum of its proper divisors (2095010).

1981630 is a wasteful number, since it uses less digits than its factorization.

1981630 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28323.

The product of its (nonzero) digits is 1296, while the sum is 28.

The square root of 1981630 is about 1407.7038040724. The cubic root of 1981630 is about 125.6051720726.

The spelling of 1981630 in words is "one million, nine hundred eighty-one thousand, six hundred thirty".