1981407 has 16 divisors (see below), whose sum is σ = 2751840. Its totient is φ = 1267200.

The previous prime is 1981403. The next prime is 1981409. The reversal of 1981407 is 7041891.

It is not a de Polignac number, because 1981407 - 2² = 1981403 is a prime.

It is a super-3 number, since 3×1981407³ = 23336855310901278429, which contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1981403) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10857 + ... + 11037.

It is an arithmetic number, because the mean of its divisors is an integer number (171990).

2^1981407 is an apocalyptic number.

1981407 is a deficient number, since it is larger than the sum of its proper divisors (770433).

1981407 is a wasteful number, since it uses less digits than its factorization.

1981407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 314.

The product of its (nonzero) digits is 2016, while the sum is 30.

The square root of 1981407 is about 1407.6245948405. The cubic root of 1981407 is about 125.6004602942.

The spelling of 1981407 in words is "one million, nine hundred eighty-one thousand, four hundred seven".