18641697984 has 756 divisors, whose sum is σ = 71366231664. Its totient is φ = 4602673152.

The previous prime is 18641697953. The next prime is 18641697989. The reversal of 18641697984 is 48979614681.

It is a Smith number, since the sum of its digits (63) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a nude number because it is divisible by every one of its digits.

Its product of digits (20901888) is a multiple of the sum of its prime factors (162).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18641697989) by changing a digit.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 396631849 + ... + 396631895.

Almost surely, 2^18641697984 is an apocalyptic number.

18641697984 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18641697984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35683115832).

18641697984 is an abundant number, since it is smaller than the sum of its proper divisors (52724533680).

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

18641697984 is a wasteful number, since it uses less digits than its factorization.

18641697984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 162 (or 95 counting only the distinct ones).

The product of its digits is 20901888, while the sum is 63.

The spelling of 18641697984 in words is "eighteen billion, six hundred forty-one million, six hundred ninety-seven thousand, nine hundred eighty-four".