1216257722 has 4 divisors (see below), whose sum is σ = 1824386586. Its totient is φ = 608128860.

The previous prime is 1216257719. The next prime is 1216257769. The reversal of 1216257722 is 2277526121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 2277526121 = 13 ⋅175194317.

It can be written as a sum of positive squares in only one way, i.e., 810597841 + 405659881 = 28471^2 + 20141^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 304064429 + ... + 304064432.

Almost surely, 2^1216257722 is an apocalyptic number.

1216257722 is a deficient number, since it is larger than the sum of its proper divisors (608128864).

1216257722 is an equidigital number, since it uses as much as digits as its factorization.

1216257722 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 608128863.

The product of its digits is 23520, while the sum is 35.

The square root of 1216257722 is about 34874.8866951564. The cubic root of 1216257722 is about 1067.4360605009.

The spelling of 1216257722 in words is "one billion, two hundred sixteen million, two hundred fifty-seven thousand, seven hundred twenty-two".