1216643642 has 16 divisors (see below), whose sum is σ = 1836670464. Its totient is φ = 604428000.

The previous prime is 1216643633. The next prime is 1216643647. The reversal of 1216643642 is 2463466121.

It is not an unprimeable number, because it can be changed into a prime (1216643647) 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, 503417 + ... + 505827.

It is an arithmetic number, because the mean of its divisors is an integer number (114791904).

Almost surely, 2^1216643642 is an apocalyptic number.

1216643642 is a deficient number, since it is larger than the sum of its proper divisors (620026822).

1216643642 is a wasteful number, since it uses less digits than its factorization.

1216643642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3925.

The product of its digits is 41472, while the sum is 35.

The square root of 1216643642 is about 34880.4191775271. The cubic root of 1216643642 is about 1067.5489481328.

The spelling of 1216643642 in words is "one billion, two hundred sixteen million, six hundred forty-three thousand, six hundred forty-two".