1221212020111 has 16 divisors (see below), whose sum is σ = 1297410857568. Its totient is φ = 1145499264000.

The previous prime is 1221212020097. The next prime is 1221212020117. The reversal of 1221212020111 is 1110202121221.

It is a cyclic number.

It is not a de Polignac number, because 1221212020111 - 2¹¹ = 1221212018063 is a prime.

It is a super-3 number, since 3×1221212020111³ (a number of 37 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221212020117) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 35585661 + ... + 35619961.

It is an arithmetic number, because the mean of its divisors is an integer number (81088178598).

Almost surely, 2^{1221212020111} is an apocalyptic number.

1221212020111 is a deficient number, since it is larger than the sum of its proper divisors (76198837457).

1221212020111 is a wasteful number, since it uses less digits than its factorization.

1221212020111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41322.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 1221212020111 its reverse (1110202121221), we get a palindrome (2331414141332).

The spelling of 1221212020111 in words is "one trillion, two hundred twenty-one billion, two hundred twelve million, twenty thousand, one hundred eleven".