1020400243523 has 4 divisors (see below), whose sum is σ = 1020762218760. Its totient is φ = 1020038268288.

The previous prime is 1020400243463. The next prime is 1020400243547. The reversal of 1020400243523 is 3253420040201.

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 1020400243523 - 2²² = 1020396049219 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1020400243492 and 1020400243501.

It is not an unprimeable number, because it can be changed into a prime (1020400243823) 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, 180983390 + ... + 180989027.

It is an arithmetic number, because the mean of its divisors is an integer number (255190554690).

Almost surely, 2^{1020400243523} is an apocalyptic number.

1020400243523 is a deficient number, since it is larger than the sum of its proper divisors (361975237).

1020400243523 is an equidigital number, since it uses as much as digits as its factorization.

1020400243523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 361975236.

The product of its (nonzero) digits is 5760, while the sum is 26.

Adding to 1020400243523 its reverse (3253420040201), we get a palindrome (4273820283724).

The spelling of 1020400243523 in words is "one trillion, twenty billion, four hundred million, two hundred forty-three thousand, five hundred twenty-three".