400994081280 has 320 divisors, whose sum is σ = 1533934321920. Its totient is φ = 98706014208.

The previous prime is 400994081249. The next prime is 400994081281. The reversal of 400994081280 is 82180499004.

400994081280 is a `hidden beast` number, since 400 + 9 + 94 + 0 + 81 + 2 + 80 = 666.

It is a tau number, because it is divible by the number of its divisors (320).

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 (400994081281) 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, 675429 + ... + 1121691.

It is an arithmetic number, because the mean of its divisors is an integer number (4793544756).

Almost surely, 2^400994081280 is an apocalyptic number.

400994081280 is a gapful number since it is divisible by the number (40) 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 400994081280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (766967160960).

400994081280 is an abundant number, since it is smaller than the sum of its proper divisors (1132940240640).

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

400994081280 is a wasteful number, since it uses less digits than its factorization.

400994081280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 446308 (or 446286 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 45.

The spelling of 400994081280 in words is "four hundred billion, nine hundred ninety-four million, eighty-one thousand, two hundred eighty".