1899681 has 12 divisors (see below), whose sum is σ = 2946672. Its totient is φ = 1085448.

The previous prime is 1899673. The next prime is 1899683. The reversal of 1899681 is 1869981.

It is not a de Polignac number, because 1899681 - 2³ = 1899673 is a prime.

It is a super-2 number, since 2×1899681² = 7217575803522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1899683) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6315 + ... + 6608.

It is an arithmetic number, because the mean of its divisors is an integer number (245556).

2^1899681 is an apocalyptic number.

It is an amenable number.

1899681 is a deficient number, since it is larger than the sum of its proper divisors (1046991).

1899681 is a wasteful number, since it uses less digits than its factorization.

1899681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12940 (or 12933 counting only the distinct ones).

The product of its digits is 31104, while the sum is 42.

The square root of 1899681 is about 1378.2891568898. The cubic root of 1899681 is about 123.8493009718.

It can be divided in two parts, 189 and 9681, that added together give a triangular number (9870 = T₁₄₀).

The spelling of 1899681 in words is "one million, eight hundred ninety-nine thousand, six hundred eighty-one".