400013280 has 72 divisors (see below), whose sum is σ = 1365050232. Its totient is φ = 106669824.

The previous prime is 400013279. The next prime is 400013311. The reversal of 400013280 is 82310004.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (18).

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 11 ways as a sum of consecutive naturals, for example, 137454 + ... + 140333.

It is an arithmetic number, because the mean of its divisors is an integer number (18959031).

Almost surely, 2^400013280 is an apocalyptic number.

400013280 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

400013280 is an abundant number, since it is smaller than the sum of its proper divisors (965036952).

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

400013280 is a wasteful number, since it uses less digits than its factorization.

400013280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 277808 (or 277797 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 400013280 is about 20000.3319972444. The cubic root of 400013280 is about 736.8144536276.

Adding to 400013280 its reverse (82310004), we get a palindrome (482323284).

The spelling of 400013280 in words is "four hundred million, thirteen thousand, two hundred eighty".