1021211660405 has 8 divisors (see below), whose sum is σ = 1225636908984. Its totient is φ = 816847384000.

The previous prime is 1021211660387. The next prime is 1021211660459. The reversal of 1021211660405 is 5040661121201.

It can be written as a sum of positive squares in 4 ways, for example, as 3064065316 + 1018147595089 = 55354^2 + 1009033^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1021211660405 - 2¹⁸ = 1021211398261 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15206186 + ... + 15273195.

It is an arithmetic number, because the mean of its divisors is an integer number (153204613623).

Almost surely, 2^{1021211660405} is an apocalyptic number.

It is an amenable number.

1021211660405 is a deficient number, since it is larger than the sum of its proper divisors (204425248579).

1021211660405 is an equidigital number, since it uses as much as digits as its factorization.

1021211660405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30486087.

The product of its (nonzero) digits is 2880, while the sum is 29.

Adding to 1021211660405 its reverse (5040661121201), we get a palindrome (6061872781606).

The spelling of 1021211660405 in words is "one trillion, twenty-one billion, two hundred eleven million, six hundred sixty thousand, four hundred five".