66490826400 has 432 divisors, whose sum is σ = 244450166688. Its totient is φ = 17635968000.

The previous prime is 66490826399. The next prime is 66490826407. The reversal of 66490826400 is 462809466.

It is a tau number, because it is divible by the number of its divisors (432).

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

It is not an unprimeable number, because it can be changed into a prime (66490826407) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 41017590 + ... + 41019210.

Almost surely, 2^66490826400 is an apocalyptic number.

66490826400 is a gapful number since it is divisible by the number (60) 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 66490826400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (122225083344).

66490826400 is an abundant number, since it is smaller than the sum of its proper divisors (177959340288).

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

66490826400 is a wasteful number, since it uses less digits than its factorization.

66490826400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1867 (or 1842 counting only the distinct ones).

The product of its (nonzero) digits is 497664, while the sum is 45.

The spelling of 66490826400 in words is "sixty-six billion, four hundred ninety million, eight hundred twenty-six thousand, four hundred".