631216109 has 2 divisors, whose sum is σ = 631216110. Its totient is φ = 631216108.

The previous prime is 631216093. The next prime is 631216121. The reversal of 631216109 is 901612136.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 353327209 + 277888900 = 18797^2 + 16670^2 .

It is a cyclic number.

It is not a de Polignac number, because 631216109 - 2⁴ = 631216093 is a prime.

It is a super-2 number, since 2×631216109² = 796867552522199762, which contains 22 as substring.

It is a Chen prime.

It is equal to p_32867210 and since 631216109 and 32867210 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (631216139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315608054 + 315608055.

It is an arithmetic number, because the mean of its divisors is an integer number (315608055).

Almost surely, 2^631216109 is an apocalyptic number.

It is an amenable number.

631216109 is a deficient number, since it is larger than the sum of its proper divisors (1).

631216109 is an equidigital number, since it uses as much as digits as its factorization.

631216109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1944, while the sum is 29.

The square root of 631216109 is about 25124.0145876410. The cubic root of 631216109 is about 857.8131336337.

The spelling of 631216109 in words is "six hundred thirty-one million, two hundred sixteen thousand, one hundred nine".