1681407 has 24 divisors (see below), whose sum is σ = 2990624. Its totient is φ = 886464.

The previous prime is 1681403. The next prime is 1681411. The reversal of 1681407 is 7041861.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1681403) and next prime (1681411).

It is not a de Polignac number, because 1681407 - 2² = 1681403 is a prime.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1681403) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 208 + ... + 1845.

2^1681407 is an apocalyptic number.

1681407 is a deficient number, since it is larger than the sum of its proper divisors (1309217).

1681407 is a wasteful number, since it uses less digits than its factorization.

1681407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2079 (or 2076 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 27.

The square root of 1681407 is about 1296.6907881218. The cubic root of 1681407 is about 118.9116166925.

The spelling of 1681407 in words is "one million, six hundred eighty-one thousand, four hundred seven".