216345631 has 2 divisors, whose sum is σ = 216345632. Its totient is φ = 216345630.

The previous prime is 216345617. The next prime is 216345637. The reversal of 216345631 is 136543612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 216345631 - 2¹¹ = 216343583 is a prime.

It is a super-2 number, since 2×216345631² = 93610864105576322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 216345593 and 216345602.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (216345637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108172815 + 108172816.

It is an arithmetic number, because the mean of its divisors is an integer number (108172816).

Almost surely, 2^216345631 is an apocalyptic number.

216345631 is a deficient number, since it is larger than the sum of its proper divisors (1).

216345631 is an equidigital number, since it uses as much as digits as its factorization.

216345631 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12960, while the sum is 31.

The square root of 216345631 is about 14708.6923620015. The cubic root of 216345631 is about 600.3198581580.

The spelling of 216345631 in words is "two hundred sixteen million, three hundred forty-five thousand, six hundred thirty-one".