645453301421 has 4 divisors (see below), whose sum is σ = 651719838432. Its totient is φ = 639186764412.

The previous prime is 645453301417. The next prime is 645453301439. The reversal of 645453301421 is 124103354546.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 645453301421 - 2² = 645453301417 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 (645453301411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3133268351 + ... + 3133268556.

It is an arithmetic number, because the mean of its divisors is an integer number (162929959608).

Almost surely, 2^645453301421 is an apocalyptic number.

It is an amenable number.

645453301421 is a deficient number, since it is larger than the sum of its proper divisors (6266537011).

645453301421 is a wasteful number, since it uses less digits than its factorization.

645453301421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6266537010.

The product of its (nonzero) digits is 172800, while the sum is 38.

Adding to 645453301421 its reverse (124103354546), we get a palindrome (769556655967).

The spelling of 645453301421 in words is "six hundred forty-five billion, four hundred fifty-three million, three hundred one thousand, four hundred twenty-one".