1981770 has 32 divisors (see below), whose sum is σ = 5436288. Its totient is φ = 452928.

The previous prime is 1981753. The next prime is 1981787. The reversal of 1981770 is 771891.

It is an interprime number because it is at equal distance from previous prime (1981753) and next prime (1981787).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4509 + ... + 4928.

It is an arithmetic number, because the mean of its divisors is an integer number (169884).

2^1981770 is an apocalyptic number.

1981770 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1981770 is an abundant number, since it is smaller than the sum of its proper divisors (3454518).

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

1981770 is a wasteful number, since it uses less digits than its factorization.

1981770 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9454.

The product of its (nonzero) digits is 3528, while the sum is 33.

The square root of 1981770 is about 1407.7535295640. The cubic root of 1981770 is about 125.6081299591.

The spelling of 1981770 in words is "one million, nine hundred eighty-one thousand, seven hundred seventy".