31551205450216 has 8 divisors (see below), whose sum is σ = 59158510219170. Its totient is φ = 15775602725104.

The previous prime is 31551205450159. The next prime is 31551205450217. The reversal of 31551205450216 is 61205450215513.

It can be written as a sum of positive squares in only one way, i.e., 31536648062500 + 14557387716 = 5615750^2 + 120654^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-3 number, since 3×31551205450216³ (a number of 41 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (31551205450217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1971950340631 + ... + 1971950340646.

Almost surely, 2^{31551205450216} is an apocalyptic number.

It is an amenable number.

31551205450216 is a deficient number, since it is larger than the sum of its proper divisors (27607304768954).

31551205450216 is a wasteful number, since it uses less digits than its factorization.

31551205450216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3943900681283 (or 3943900681279 counting only the distinct ones).

The product of its (nonzero) digits is 180000, while the sum is 40.

Adding to 31551205450216 its reverse (61205450215513), we get a palindrome (92756655665729).

The spelling of 31551205450216 in words is "thirty-one trillion, five hundred fifty-one billion, two hundred five million, four hundred fifty thousand, two hundred sixteen".