645121302533 has 4 divisors (see below), whose sum is σ = 645495721728. Its totient is φ = 644746883340.

The previous prime is 645121302481. The next prime is 645121302577. The reversal of 645121302533 is 335203121546.

It is a happy number.

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 645121302533 - 2⁸ = 645121302277 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 645121302493 and 645121302502.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645121302593) 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, 187207013 + ... + 187210458.

It is an arithmetic number, because the mean of its divisors is an integer number (161373930432).

Almost surely, 2^645121302533 is an apocalyptic number.

It is an amenable number.

645121302533 is a deficient number, since it is larger than the sum of its proper divisors (374419195).

645121302533 is a wasteful number, since it uses less digits than its factorization.

645121302533 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 374419194.

The product of its (nonzero) digits is 64800, while the sum is 35.

The spelling of 645121302533 in words is "six hundred forty-five billion, one hundred twenty-one million, three hundred two thousand, five hundred thirty-three".