1216156506 has 24 divisors (see below), whose sum is σ = 2583810240. Its totient is φ = 381538752.

The previous prime is 1216156493. The next prime is 1216156507. The reversal of 1216156506 is 6056516121.

It is a super-2 number, since 2×1216156506² = 2958073294172256072, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1216156507) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 348946 + ... + 352413.

It is an arithmetic number, because the mean of its divisors is an integer number (107658760).

Almost surely, 2^1216156506 is an apocalyptic number.

1216156506 is an abundant number, since it is smaller than the sum of its proper divisors (1367653734).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1216156506 is a wasteful number, since it uses less digits than its factorization.

1216156506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 701398 (or 701381 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 33.

The square root of 1216156506 is about 34873.4355348021. The cubic root of 1216156506 is about 1067.4064492863.

The spelling of 1216156506 in words is "one billion, two hundred sixteen million, one hundred fifty-six thousand, five hundred six".