16215181231 has 2 divisors, whose sum is σ = 16215181232. Its totient is φ = 16215181230.

The previous prime is 16215181211. The next prime is 16215181237. The reversal of 16215181231 is 13218151261.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 16215181231 - 2⁹ = 16215180719 is a prime.

It is a super-4 number, since 4×16215181231⁴ (a number of 42 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a junction number, because it is equal to n+sod(n) for n = 16215181193 and 16215181202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16215181237) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8107590615 + 8107590616.

It is an arithmetic number, because the mean of its divisors is an integer number (8107590616).

Almost surely, 2^16215181231 is an apocalyptic number.

16215181231 is a deficient number, since it is larger than the sum of its proper divisors (1).

16215181231 is an equidigital number, since it uses as much as digits as its factorization.

16215181231 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2880, while the sum is 31.

The spelling of 16215181231 in words is "sixteen billion, two hundred fifteen million, one hundred eighty-one thousand, two hundred thirty-one".