1221215020871 has 2 divisors, whose sum is σ = 1221215020872. Its totient is φ = 1221215020870.

The previous prime is 1221215020867. The next prime is 1221215020981. The reversal of 1221215020871 is 1780205121221.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1221215020871 - 2² = 1221215020867 is a prime.

It is a super-2 number, since 2×1221215020871² (a number of 25 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221215020841) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610607510435 + 610607510436.

It is an arithmetic number, because the mean of its divisors is an integer number (610607510436).

Almost surely, 2^{1221215020871} is an apocalyptic number.

1221215020871 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221215020871 is an equidigital number, since it uses as much as digits as its factorization.

1221215020871 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4480, while the sum is 32.

The spelling of 1221215020871 in words is "one trillion, two hundred twenty-one billion, two hundred fifteen million, twenty thousand, eight hundred seventy-one".