1242005205511 has 4 divisors (see below), whose sum is σ = 1419434520592. Its totient is φ = 1064575890432.

The previous prime is 1242005205479. The next prime is 1242005205577. The reversal of 1242005205511 is 1155025002421.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1242005205511 - 2⁵ = 1242005205479 is a prime.

It is a super-2 number, since 2×1242005205511² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1242005205511.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1242005215511) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 88714657530 + ... + 88714657543.

It is an arithmetic number, because the mean of its divisors is an integer number (354858630148).

Almost surely, 2^{1242005205511} is an apocalyptic number.

1242005205511 is a deficient number, since it is larger than the sum of its proper divisors (177429315081).

1242005205511 is an equidigital number, since it uses as much as digits as its factorization.

1242005205511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 177429315080.

The product of its (nonzero) digits is 4000, while the sum is 28.

The spelling of 1242005205511 in words is "one trillion, two hundred forty-two billion, five million, two hundred five thousand, five hundred eleven".