644719161474 has 128 divisors (see below), whose sum is σ = 1549982304000. Its totient is φ = 197951330304.

The previous prime is 644719161433. The next prime is 644719161529. The reversal of 644719161474 is 474161917446.

644719161474 is a `hidden beast` number, since 6 + 4 + 4 + 7 + 1 + 9 + 161 + 474 = 666.

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

It is a self number, because there is not a number n which added to its sum of digits gives 644719161474.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 61227442 + ... + 61237970.

It is an arithmetic number, because the mean of its divisors is an integer number (12109236750).

Almost surely, 2^644719161474 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 644719161474, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (774991152000).

644719161474 is an abundant number, since it is smaller than the sum of its proper divisors (905263142526).

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

644719161474 is a wasteful number, since it uses less digits than its factorization.

644719161474 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12209 (or 12203 counting only the distinct ones).

The product of its digits is 4064256, while the sum is 54.

The spelling of 644719161474 in words is "six hundred forty-four billion, seven hundred nineteen million, one hundred sixty-one thousand, four hundred seventy-four".