19145681664 has 144 divisors (see below), whose sum is σ = 53734961280. Its totient is φ = 6035005440.

The previous prime is 19145681641. The next prime is 19145681671. The reversal of 19145681664 is 46618654191.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12504579 + ... + 12506109.

Almost surely, 2^19145681664 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19145681664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26867480640).

19145681664 is an abundant number, since it is smaller than the sum of its proper divisors (34589279616).

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

19145681664 is a wasteful number, since it uses less digits than its factorization.

19145681664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2426 (or 2412 counting only the distinct ones).

The product of its digits is 1244160, while the sum is 51.

The spelling of 19145681664 in words is "nineteen billion, one hundred forty-five million, six hundred eighty-one thousand, six hundred sixty-four".