1981380 has 24 divisors (see below), whose sum is σ = 5548032. Its totient is φ = 528352.

The previous prime is 1981361. The next prime is 1981393. The reversal of 1981380 is 831891.

It is a super-3 number, since 3×1981380³ = 23335901312292216000, which contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16452 + ... + 16571.

It is an arithmetic number, because the mean of its divisors is an integer number (231168).

2^1981380 is an apocalyptic number.

1981380 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1981380 is an abundant number, since it is smaller than the sum of its proper divisors (3566652).

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

1981380 is a wasteful number, since it uses less digits than its factorization.

1981380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33035 (or 33033 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 30.

The square root of 1981380 is about 1407.6150041826. The cubic root of 1981380 is about 125.5998897858.

The spelling of 1981380 in words is "one million, nine hundred eighty-one thousand, three hundred eighty".