1981930 has 8 divisors (see below), whose sum is σ = 3567492. Its totient is φ = 792768.

The previous prime is 1981921. The next prime is 1981939. The reversal of 1981930 is 391891.

It is an interprime number because it is at equal distance from previous prime (1981921) and next prime (1981939).

It can be written as a sum of positive squares in 2 ways, for example, as 1830609 + 151321 = 1353^2 + 389^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 1981892 and 1981901.

It is not an unprimeable number, because it can be changed into a prime (1981939) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 99087 + ... + 99106.

2^1981930 is an apocalyptic number.

1981930 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1981930 is a deficient number, since it is larger than the sum of its proper divisors (1585562).

1981930 is a wasteful number, since it uses less digits than its factorization.

1981930 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198200.

The product of its (nonzero) digits is 1944, while the sum is 31.

The square root of 1981930 is about 1407.8103565466. The cubic root of 1981930 is about 125.6115102303.

The spelling of 1981930 in words is "one million, nine hundred eighty-one thousand, nine hundred thirty".