1221211219977 has 24 divisors (see below), whose sum is σ = 2103618501504. Its totient is φ = 667494330624.

The previous prime is 1221211219961. The next prime is 1221211219981. The reversal of 1221211219977 is 7799121121221.

It is not a de Polignac number, because 1221211219977 - 2⁴ = 1221211219961 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1221211219957) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 421396488 + ... + 421399385.

It is an arithmetic number, because the mean of its divisors is an integer number (87650770896).

Almost surely, 2^{1221211219977} is an apocalyptic number.

It is an amenable number.

1221211219977 is a deficient number, since it is larger than the sum of its proper divisors (882407281527).

1221211219977 is a wasteful number, since it uses less digits than its factorization.

1221211219977 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 842795909 (or 842795906 counting only the distinct ones).

The product of its digits is 63504, while the sum is 45.

The spelling of 1221211219977 in words is "one trillion, two hundred twenty-one billion, two hundred eleven million, two hundred nineteen thousand, nine hundred seventy-seven".