1216857069 has 6 divisors (see below), whose sum is σ = 1757682446. Its totient is φ = 811238040.

The previous prime is 1216857053. The next prime is 1216857091. The reversal of 1216857069 is 9607586121.

1216857069 is a `hidden beast` number, since 1 + 2 + 16 + 8 + 570 + 69 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1214174025 + 2683044 = 34845^2 + 1638^2 .

It is not a de Polignac number, because 1216857069 - 2⁴ = 1216857053 is a prime.

It is a super-2 number, since 2×1216857069² = 2961482252750541522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216857029) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 67603162 + ... + 67603179.

Almost surely, 2^1216857069 is an apocalyptic number.

It is an amenable number.

1216857069 is a deficient number, since it is larger than the sum of its proper divisors (540825377).

1216857069 is a wasteful number, since it uses less digits than its factorization.

1216857069 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135206347 (or 135206344 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 45.

The square root of 1216857069 is about 34883.4784532735. The cubic root of 1216857069 is about 1067.6113686148.

The spelling of 1216857069 in words is "one billion, two hundred sixteen million, eight hundred fifty-seven thousand, sixty-nine".