2639969 has 2 divisors, whose sum is σ = 2639970. Its totient is φ = 2639968.

The previous prime is 2639953. The next prime is 2639971. The reversal of 2639969 is 9699362.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2131600 + 508369 = 1460^2 + 713^2 .

It is a cyclic number.

It is not a de Polignac number, because 2639969 - 2⁴ = 2639953 is a prime.

It is a super-2 number, since 2×2639969² = 13938872641922, which contains 22 as substring.

Together with 2639971, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (2639939) 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 as a sum of consecutive naturals, namely, 1319984 + 1319985.

It is an arithmetic number, because the mean of its divisors is an integer number (1319985).

2^2639969 is an apocalyptic number.

It is an amenable number.

2639969 is a deficient number, since it is larger than the sum of its proper divisors (1).

2639969 is an equidigital number, since it uses as much as digits as its factorization.

2639969 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 157464, while the sum is 44.

The square root of 2639969 is about 1624.7981413086. The cubic root of 2639969 is about 138.2079236306.

It can be divided in two parts, 2639 and 969, that multiplied together give a triangular number (2557191 = T₂₂₆₁).

The spelling of 2639969 in words is "two million, six hundred thirty-nine thousand, nine hundred sixty-nine".