644450662143450 has 48 divisors (see below), whose sum is σ = 1775819602354560. Its totient is φ = 171853509904560.

The previous prime is 644450662143439. The next prime is 644450662143479. The reversal of 644450662143450 is 54341266054446.

644450662143450 is a `hidden beast` number, since 6 + 4 + 4 + 4 + 5 + 0 + 6 + 621 + 4 + 3 + 4 + 5 + 0 = 666.

It is a super-2 number, since 2×644450662143450² (a number of 30 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 238685429074 + ... + 238685431773.

It is an arithmetic number, because the mean of its divisors is an integer number (36996241715720).

Almost surely, 2^{644450662143450} is an apocalyptic number.

644450662143450 is an abundant number, since it is smaller than the sum of its proper divisors (1131368940211110).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

644450662143450 is a wasteful number, since it uses less digits than its factorization.

644450662143450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 477370860868 (or 477370860857 counting only the distinct ones).

The product of its (nonzero) digits is 33177600, while the sum is 54.

The spelling of 644450662143450 in words is "six hundred forty-four trillion, four hundred fifty billion, six hundred sixty-two million, one hundred forty-three thousand, four hundred fifty".