631617409 has 2 divisors, whose sum is σ = 631617410. Its totient is φ = 631617408.

The previous prime is 631617401. The next prime is 631617433. The reversal of 631617409 is 904716136.

631617409 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 334158400 + 297459009 = 18280^2 + 17247^2 .

It is a cyclic number.

It is not a de Polignac number, because 631617409 - 2³ = 631617401 is a prime.

It is a super-3 number, since 3×631617409³ (a number of 27 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (631617401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315808704 + 315808705.

It is an arithmetic number, because the mean of its divisors is an integer number (315808705).

Almost surely, 2^631617409 is an apocalyptic number.

It is an amenable number.

631617409 is a deficient number, since it is larger than the sum of its proper divisors (1).

631617409 is an equidigital number, since it uses as much as digits as its factorization.

631617409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 27216, while the sum is 37.

The square root of 631617409 is about 25131.9997015757. Note that the first 3 decimals coincide. The cubic root of 631617409 is about 857.9948819976.

The spelling of 631617409 in words is "six hundred thirty-one million, six hundred seventeen thousand, four hundred nine".