394406040000 has 560 divisors, whose sum is σ = 1508505723648. Its totient is φ = 89048064000.

The previous prime is 394406039987. The next prime is 394406040019. The reversal of 394406040000 is 40604493.

It is a tau number, because it is divible by the number of its divisors (560).

It is a super-2 number, since 2×394406040000² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a self number, because there is not a number n which added to its sum of digits gives 394406040000.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 69717172 + ... + 69722828.

Almost surely, 2^394406040000 is an apocalyptic number.

394406040000 is a gapful number since it is divisible by the number (30) 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 394406040000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (754252861824).

394406040000 is an abundant number, since it is smaller than the sum of its proper divisors (1114099683648).

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

394406040000 is an equidigital number, since it uses as much as digits as its factorization.

394406040000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5782 (or 5757 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 30.

Adding to 394406040000 its reverse (40604493), we get a palindrome (394446644493).

The spelling of 394406040000 in words is "three hundred ninety-four billion, four hundred six million, forty thousand".