1216380729 has 8 divisors (see below), whose sum is σ = 1622031552. Its totient is φ = 810825200.

The previous prime is 1216380713. The next prime is 1216380749. The reversal of 1216380729 is 9270836121.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1216380729 - 2⁴ = 1216380713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1216380749) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15004 + ... + 51554.

It is an arithmetic number, because the mean of its divisors is an integer number (202753944).

Almost surely, 2^1216380729 is an apocalyptic number.

It is an amenable number.

1216380729 is a deficient number, since it is larger than the sum of its proper divisors (405650823).

1216380729 is a wasteful number, since it uses less digits than its factorization.

1216380729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47647.

The product of its (nonzero) digits is 36288, while the sum is 39.

The square root of 1216380729 is about 34876.6501975175. The cubic root of 1216380729 is about 1067.4720445633.

The spelling of 1216380729 in words is "one billion, two hundred sixteen million, three hundred eighty thousand, seven hundred twenty-nine".