1213042043021 has 4 divisors (see below), whose sum is σ = 1213056637212. Its totient is φ = 1213027448832.

The previous prime is 1213042042907. The next prime is 1213042043027. The reversal of 1213042043021 is 1203402403121.

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

It can be written as a sum of positive squares in 2 ways, for example, as 501278160100 + 711763882921 = 708010^2 + 843661^2 .

It is a cyclic number.

It is not a de Polignac number, because 1213042043021 - 2²² = 1213037848717 is a prime.

It is a super-2 number, since 2×1213042043021² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1213042043027) 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, 7171700 + ... + 7338893.

It is an arithmetic number, because the mean of its divisors is an integer number (303264159303).

Almost surely, 2^{1213042043021} is an apocalyptic number.

It is an amenable number.

1213042043021 is a deficient number, since it is larger than the sum of its proper divisors (14594191).

1213042043021 is an equidigital number, since it uses as much as digits as its factorization.

1213042043021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14594190.

The product of its (nonzero) digits is 1152, while the sum is 23.

Adding to 1213042043021 its reverse (1203402403121), we get a palindrome (2416444446142).

The spelling of 1213042043021 in words is "one trillion, two hundred thirteen billion, forty-two million, forty-three thousand, twenty-one".