644451602652433 has 8 divisors (see below), whose sum is σ = 649626839468640. Its totient is φ = 639280240971840.

The previous prime is 644451602652397. The next prime is 644451602652439. The reversal of 644451602652433 is 334256206154446.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 644451602652433 - 2¹⁷ = 644451602521361 is a prime.

It is a super-2 number, since 2×644451602652433² (a number of 30 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (644451602652439) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 968449960 + ... + 969115177.

It is an arithmetic number, because the mean of its divisors is an integer number (81203354933580).

Almost surely, 2^{644451602652433} is an apocalyptic number.

It is an amenable number.

644451602652433 is a deficient number, since it is larger than the sum of its proper divisors (5175236816207).

644451602652433 is a wasteful number, since it uses less digits than its factorization.

644451602652433 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1937567807.

The product of its (nonzero) digits is 49766400, while the sum is 55.

The spelling of 644451602652433 in words is "six hundred forty-four trillion, four hundred fifty-one billion, six hundred two million, six hundred fifty-two thousand, four hundred thirty-three".