1245813421 has 4 divisors (see below), whose sum is σ = 1279484092. Its totient is φ = 1212142752.

The previous prime is 1245813409. The next prime is 1245813463. The reversal of 1245813421 is 1243185421.

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 542237796 + 703575625 = 23286^2 + 26525^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1245813421 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1245813521) 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, 16835280 + ... + 16835353.

It is an arithmetic number, because the mean of its divisors is an integer number (319871023).

Almost surely, 2^1245813421 is an apocalyptic number.

It is an amenable number.

1245813421 is a deficient number, since it is larger than the sum of its proper divisors (33670671).

1245813421 is an equidigital number, since it uses as much as digits as its factorization.

1245813421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33670670.

The product of its digits is 7680, while the sum is 31.

The square root of 1245813421 is about 35296.0822330184. The cubic root of 1245813421 is about 1076.0133717354.

Adding to 1245813421 its reverse (1243185421), we get a palindrome (2488998842).

The spelling of 1245813421 in words is "one billion, two hundred forty-five million, eight hundred thirteen thousand, four hundred twenty-one".