1221289356862 has 16 divisors (see below), whose sum is σ = 1837294351200. Its totient is φ = 608858119008.

The previous prime is 1221289356853. The next prime is 1221289356863. The reversal of 1221289356862 is 2686539821221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221289356863) 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, 14250223 + ... + 14335669.

It is an arithmetic number, because the mean of its divisors is an integer number (114830896950).

Almost surely, 2^{1221289356862} is an apocalyptic number.

1221289356862 is a deficient number, since it is larger than the sum of its proper divisors (616004994338).

1221289356862 is a wasteful number, since it uses less digits than its factorization.

1221289356862 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106275.

The product of its digits is 4976640, while the sum is 55.

The spelling of 1221289356862 in words is "one trillion, two hundred twenty-one billion, two hundred eighty-nine million, three hundred fifty-six thousand, eight hundred sixty-two".