2981781 has 12 divisors (see below), whose sum is σ = 4698720. Its totient is φ = 1807080.

The previous prime is 2981779. The next prime is 2981819. The reversal of 2981781 is 1871892.

It is not a de Polignac number, because 2981781 - 2¹ = 2981779 is a prime.

It is a super-2 number, since 2×2981781² = 17782035863922, which contains 22 as substring.

It is an Ulam number.

It is a nialpdrome in base 9.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2981711) 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, 14961 + ... + 15158.

It is an arithmetic number, because the mean of its divisors is an integer number (391560).

2^2981781 is an apocalyptic number.

It is an amenable number.

2981781 is a deficient number, since it is larger than the sum of its proper divisors (1716939).

2981781 is a wasteful number, since it uses less digits than its factorization.

2981781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30136 (or 30133 counting only the distinct ones).

The product of its digits is 8064, while the sum is 36.

The square root of 2981781 is about 1726.7834259107. The cubic root of 2981781 is about 143.9324046174.

It can be divided in two parts, 29 and 81781, that added together give a triangular number (81810 = T₄₀₄).

The spelling of 2981781 in words is "two million, nine hundred eighty-one thousand, seven hundred eighty-one".