1305245500021 has 4 divisors (see below), whose sum is σ = 1306350704844. Its totient is φ = 1304140295200.

The previous prime is 1305245500007. The next prime is 1305245500087. The reversal of 1305245500021 is 1200055425031.

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 794362212900 + 510883287121 = 891270^2 + 714761^2 .

It is a cyclic number.

It is not a de Polignac number, because 1305245500021 - 2¹³ = 1305245491829 is a prime.

It is a super-2 number, since 2×1305245500021² (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 (1305245500621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 552600640 + ... + 552603001.

It is an arithmetic number, because the mean of its divisors is an integer number (326587676211).

Almost surely, 2^{1305245500021} is an apocalyptic number.

It is an amenable number.

1305245500021 is a deficient number, since it is larger than the sum of its proper divisors (1105204823).

1305245500021 is a wasteful number, since it uses less digits than its factorization.

1305245500021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1105204822.

The product of its (nonzero) digits is 6000, while the sum is 28.

The spelling of 1305245500021 in words is "one trillion, three hundred five billion, two hundred forty-five million, five hundred thousand, twenty-one".