18641672640 has 224 divisors, whose sum is σ = 66747298560. Its totient is φ = 4896764928.

The previous prime is 18641672629. The next prime is 18641672641. The reversal of 18641672640 is 4627614681.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18641672641) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 562779 + ... + 594981.

Almost surely, 2^18641672640 is an apocalyptic number.

18641672640 is a gapful number since it is divisible by the number (10) 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 18641672640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33373649280).

18641672640 is an abundant number, since it is smaller than the sum of its proper divisors (48105625920).

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

18641672640 is a wasteful number, since it uses less digits than its factorization.

18641672640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32296 (or 32280 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 45.

The spelling of 18641672640 in words is "eighteen billion, six hundred forty-one million, six hundred seventy-two thousand, six hundred forty".