1916681 has 8 divisors (see below), whose sum is σ = 2098824. Its totient is φ = 1739520.

The previous prime is 1916653. The next prime is 1916687. The reversal of 1916681 is 1866191.

It can be written as a sum of positive squares in 4 ways, for example, as 80656 + 1836025 = 284^2 + 1355^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1916681 - 2⁶ = 1916617 is a prime.

It is a super-2 number, since 2×1916681² = 7347332111522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1916687) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 416 + ... + 2001.

It is an arithmetic number, because the mean of its divisors is an integer number (262353).

2^1916681 is an apocalyptic number.

It is an amenable number.

1916681 is a deficient number, since it is larger than the sum of its proper divisors (182143).

1916681 is a wasteful number, since it uses less digits than its factorization.

1916681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2491.

The product of its digits is 2592, while the sum is 32.

The square root of 1916681 is about 1384.4424870684. The cubic root of 1916681 is about 124.2176415378.

The spelling of 1916681 in words is "one million, nine hundred sixteen thousand, six hundred eighty-one".