2990781 has 6 divisors (see below), whose sum is σ = 4320030. Its totient is φ = 1993848.

The previous prime is 2990777. The next prime is 2990783. The reversal of 2990781 is 1870992.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 2295225 + 695556 = 1515^2 + 834^2 .

It is not a de Polignac number, because 2990781 - 2² = 2990777 is a prime.

It is a super-2 number, since 2×2990781² = 17889541979922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2990783) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 166146 + ... + 166163.

It is an arithmetic number, because the mean of its divisors is an integer number (720005).

2^2990781 is an apocalyptic number.

It is an amenable number.

2990781 is a deficient number, since it is larger than the sum of its proper divisors (1329249).

2990781 is a wasteful number, since it uses less digits than its factorization.

2990781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 332315 (or 332312 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 36.

The square root of 2990781 is about 1729.3874638149. The cubic root of 2990781 is about 144.0770710116.

The spelling of 2990781 in words is "two million, nine hundred ninety thousand, seven hundred eighty-one".