2639881 has 2 divisors, whose sum is σ = 2639882. Its totient is φ = 2639880.

The previous prime is 2639873. The next prime is 2639887. The reversal of 2639881 is 1889362.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1974025 + 665856 = 1405^2 + 816^2 .

It is a cyclic number.

It is not a de Polignac number, because 2639881 - 2³ = 2639873 is a prime.

It is a super-2 number, since 2×2639881² = 13937943388322, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2639881.

It is not a weakly prime, because it can be changed into another prime (2639887) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1319940 + 1319941.

It is an arithmetic number, because the mean of its divisors is an integer number (1319941).

2^2639881 is an apocalyptic number.

It is an amenable number.

2639881 is a deficient number, since it is larger than the sum of its proper divisors (1).

2639881 is an equidigital number, since it uses as much as digits as its factorization.

2639881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20736, while the sum is 37.

The square root of 2639881 is about 1624.7710607960. The cubic root of 2639881 is about 138.2063879519.

The spelling of 2639881 in words is "two million, six hundred thirty-nine thousand, eight hundred eighty-one".