1821560737121 has 2 divisors, whose sum is σ = 1821560737122. Its totient is φ = 1821560737120.

The previous prime is 1821560737109. The next prime is 1821560737223. The reversal of 1821560737121 is 1217370651281.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1514019507025 + 307541230096 = 1230455^2 + 554564^2 .

It is a cyclic number.

It is not a de Polignac number, because 1821560737121 - 2¹⁴ = 1821560720737 is a prime.

It is a super-3 number, since 3×1821560737121³ (a number of 38 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (1821560137121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 910780368560 + 910780368561.

It is an arithmetic number, because the mean of its divisors is an integer number (910780368561).

Almost surely, 2^{1821560737121} is an apocalyptic number.

It is an amenable number.

1821560737121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1821560737121 is an equidigital number, since it uses as much as digits as its factorization.

1821560737121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 141120, while the sum is 44.

The spelling of 1821560737121 in words is "one trillion, eight hundred twenty-one billion, five hundred sixty million, seven hundred thirty-seven thousand, one hundred twenty-one".