1216464291 has 48 divisors (see below), whose sum is σ = 2188001280. Its totient is φ = 654203520.

The previous prime is 1216464287. The next prime is 1216464311. The reversal of 1216464291 is 1924646121.

1216464291 is a `hidden beast` number, since 1 + 2 + 1 + 6 + 4 + 642 + 9 + 1 = 666.

It is not a de Polignac number, because 1216464291 - 2² = 1216464287 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1216464241) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 43486 + ... + 65756.

It is an arithmetic number, because the mean of its divisors is an integer number (45583360).

Almost surely, 2^1216464291 is an apocalyptic number.

1216464291 is a deficient number, since it is larger than the sum of its proper divisors (971536989).

1216464291 is a wasteful number, since it uses less digits than its factorization.

1216464291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22321 (or 22298 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The square root of 1216464291 is about 34877.8481417647. The cubic root of 1216464291 is about 1067.4964881317.

The spelling of 1216464291 in words is "one billion, two hundred sixteen million, four hundred sixty-four thousand, two hundred ninety-one".