645421420763 has 4 divisors (see below), whose sum is σ = 737624480880. Its totient is φ = 553218360648.

The previous prime is 645421420741. The next prime is 645421420801. The reversal of 645421420763 is 367024124546.

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 645421420763 - 2⁸ = 645421420507 is a prime.

It is not an unprimeable number, because it can be changed into a prime (645421420463) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 46101530048 + ... + 46101530061.

It is an arithmetic number, because the mean of its divisors is an integer number (184406120220).

Almost surely, 2^645421420763 is an apocalyptic number.

645421420763 is a deficient number, since it is larger than the sum of its proper divisors (92203060117).

645421420763 is an equidigital number, since it uses as much as digits as its factorization.

645421420763 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92203060116.

The product of its (nonzero) digits is 967680, while the sum is 44.

The spelling of 645421420763 in words is "six hundred forty-five billion, four hundred twenty-one million, four hundred twenty thousand, seven hundred sixty-three".