645121892824 has 8 divisors (see below), whose sum is σ = 1209603549060. Its totient is φ = 322560946408.

The previous prime is 645121892813. The next prime is 645121892861. The reversal of 645121892824 is 428298121546.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 40320118294 + ... + 40320118309.

Almost surely, 2^645121892824 is an apocalyptic number.

It is an amenable number.

645121892824 is a deficient number, since it is larger than the sum of its proper divisors (564481656236).

645121892824 is a wasteful number, since it uses less digits than its factorization.

645121892824 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80640236609 (or 80640236605 counting only the distinct ones).

The product of its digits is 2211840, while the sum is 52.

The spelling of 645121892824 in words is "six hundred forty-five billion, one hundred twenty-one million, eight hundred ninety-two thousand, eight hundred twenty-four".