1212721667 has 8 divisors (see below), whose sum is σ = 1270266624. Its totient is φ = 1155578248.

The previous prime is 1212721661. The next prime is 1212721703. The reversal of 1212721667 is 7661272121.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1212721667 is a prime.

It is a super-2 number, since 2×1212721667² = 2941387683222517778, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1212721661) 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, 94193 + ... + 106290.

It is an arithmetic number, because the mean of its divisors is an integer number (158783328).

Almost surely, 2^1212721667 is an apocalyptic number.

1212721667 is a deficient number, since it is larger than the sum of its proper divisors (57544957).

1212721667 is a wasteful number, since it uses less digits than its factorization.

1212721667 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 200769.

The product of its digits is 14112, while the sum is 35.

The square root of 1212721667 is about 34824.1535001211. The cubic root of 1212721667 is about 1066.4005956263.

Adding to 1212721667 its reverse (7661272121), we get a palindrome (8873993788).

The spelling of 1212721667 in words is "one billion, two hundred twelve million, seven hundred twenty-one thousand, six hundred sixty-seven".