2638890 has 48 divisors (see below), whose sum is σ = 6949800. Its totient is φ = 694656.

The previous prime is 2638879. The next prime is 2638897. The reversal of 2638890 is 988362.

It can be written as a sum of positive squares in 4 ways, for example, as 1734489 + 904401 = 1317^2 + 951^2 .

It is not an unprimeable number, because it can be changed into a prime (2638897) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9676 + ... + 9944.

2^2638890 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2638890, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3474900).

2638890 is an abundant number, since it is smaller than the sum of its proper divisors (4310910).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2638890 is a wasteful number, since it uses less digits than its factorization.

2638890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 391 (or 388 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 2638890 is about 1624.4660661276. The cubic root of 2638890 is about 138.1890917591.

The spelling of 2638890 in words is "two million, six hundred thirty-eight thousand, eight hundred ninety".