20671660800 has 648 divisors, whose sum is σ = 85246377216. Its totient is φ = 4681359360.

The previous prime is 20671660783. The next prime is 20671660813. The reversal of 20671660800 is 806617602.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 67334247 + ... + 67334553.

Almost surely, 2^20671660800 is an apocalyptic number.

20671660800 is a gapful number since it is divisible by the number (20) 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 20671660800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42623188608).

20671660800 is an abundant number, since it is smaller than the sum of its proper divisors (64574716416).

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

20671660800 is a wasteful number, since it uses less digits than its factorization.

20671660800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 513 (or 491 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The spelling of 20671660800 in words is "twenty billion, six hundred seventy-one million, six hundred sixty thousand, eight hundred".