1216166118531 has 64 divisors (see below), whose sum is σ = 2142920779776. Its totient is φ = 595255449600.

The previous prime is 1216166118511. The next prime is 1216166118569. The reversal of 1216166118531 is 1358116616121.

It is not a de Polignac number, because 1216166118531 - 2⁵ = 1216166118499 is a prime.

It is a super-2 number, since 2×1216166118531² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1216166118511) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1515900 + ... + 2174921.

It is an arithmetic number, because the mean of its divisors is an integer number (33483137184).

Almost surely, 2^{1216166118531} is an apocalyptic number.

1216166118531 is a deficient number, since it is larger than the sum of its proper divisors (926754661245).

1216166118531 is a wasteful number, since it uses less digits than its factorization.

1216166118531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3690932.

The product of its digits is 51840, while the sum is 42.

The spelling of 1216166118531 in words is "one trillion, two hundred sixteen billion, one hundred sixty-six million, one hundred eighteen thousand, five hundred thirty-one".