1681380 has 36 divisors (see below), whose sum is σ = 5100732. Its totient is φ = 448320.

The previous prime is 1681363. The next prime is 1681397. The reversal of 1681380 is 831861.

It is an interprime number because it is at equal distance from previous prime (1681363) and next prime (1681397).

It can be written as a sum of positive squares in 2 ways, for example, as 553536 + 1127844 = 744^2 + 1062^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4491 + ... + 4850.

It is an arithmetic number, because the mean of its divisors is an integer number (141687).

2^1681380 is an apocalyptic number.

1681380 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1681380 is an abundant number, since it is smaller than the sum of its proper divisors (3419352).

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

1681380 is a wasteful number, since it uses less digits than its factorization.

1681380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9356 (or 9351 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 1681380 is about 1296.6803769626. The cubic root of 1681380 is about 118.9109801956.

The spelling of 1681380 in words is "one million, six hundred eighty-one thousand, three hundred eighty".