1221011121937 has 2 divisors, whose sum is σ = 1221011121938. Its totient is φ = 1221011121936.

The previous prime is 1221011121923. The next prime is 1221011122091. The reversal of 1221011121937 is 7391211101221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 976570862656 + 244440259281 = 988216^2 + 494409^2 .

It is an emirp because it is prime and its reverse (7391211101221) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221011121937 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1221011121899 and 1221011121908.

It is not a weakly prime, because it can be changed into another prime (1221011121907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610505560968 + 610505560969.

It is an arithmetic number, because the mean of its divisors is an integer number (610505560969).

Almost surely, 2^{1221011121937} is an apocalyptic number.

It is an amenable number.

1221011121937 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221011121937 is an equidigital number, since it uses as much as digits as its factorization.

1221011121937 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1512, while the sum is 31.

The spelling of 1221011121937 in words is "one trillion, two hundred twenty-one billion, eleven million, one hundred twenty-one thousand, nine hundred thirty-seven".