1981290 has 32 divisors (see below), whose sum is σ = 4792896. Its totient is φ = 524160.

The previous prime is 1981277. The next prime is 1981297. The reversal of 1981290 is 921891.

It is a super-3 number, since 3×1981290³ = 23332721504702067000, which contains 333 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (1981297) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6174 + ... + 6486.

It is an arithmetic number, because the mean of its divisors is an integer number (149778).

2^1981290 is an apocalyptic number.

1981290 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1981290 is an abundant number, since it is smaller than the sum of its proper divisors (2811606).

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

1981290 is a wasteful number, since it uses less digits than its factorization.

1981290 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 534.

The product of its (nonzero) digits is 1296, while the sum is 30.

The square root of 1981290 is about 1407.5830348509. The cubic root of 1981290 is about 125.5979880538.

The spelling of 1981290 in words is "one million, nine hundred eighty-one thousand, two hundred ninety".