19661323164 has 24 divisors (see below), whose sum is σ = 52430195328. Its totient is φ = 5617520880.

The previous prime is 19661323109. The next prime is 19661323183. The reversal of 19661323164 is 46132316691.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 117031602 + ... + 117031769.

It is an arithmetic number, because the mean of its divisors is an integer number (2184591472).

Almost surely, 2^19661323164 is an apocalyptic number.

19661323164 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

19661323164 is an abundant number, since it is smaller than the sum of its proper divisors (32768872164).

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

19661323164 is a wasteful number, since it uses less digits than its factorization.

19661323164 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 234063385 (or 234063383 counting only the distinct ones).

The product of its digits is 139968, while the sum is 42.

The spelling of 19661323164 in words is "nineteen billion, six hundred sixty-one million, three hundred twenty-three thousand, one hundred sixty-four".