2209631 has 2 divisors, whose sum is σ = 2209632. Its totient is φ = 2209630.

The previous prime is 2209607. The next prime is 2209639. The reversal of 2209631 is 1369022.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2209631 - 2¹⁸ = 1947487 is a prime.

It is a super-2 number, since 2×2209631² = 9764938312322, which contains 22 as substring.

It is a Sophie Germain prime.

It is an Ulam number.

It is equal to p₁₆₃₃₂₈ and since 2209631 and 163328 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 2209597 and 2209606.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2209639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1104815 + 1104816.

It is an arithmetic number, because the mean of its divisors is an integer number (1104816).

2^2209631 is an apocalyptic number.

2209631 is a deficient number, since it is larger than the sum of its proper divisors (1).

2209631 is an equidigital number, since it uses as much as digits as its factorization.

2209631 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 2209631 is about 1486.4827614204. The cubic root of 2209631 is about 130.2486562319.

The spelling of 2209631 in words is "two million, two hundred nine thousand, six hundred thirty-one".