400531320 has 96 divisors (see below), whose sum is σ = 1487697120. Its totient is φ = 91549440.

The previous prime is 400531309. The next prime is 400531331. The reversal of 400531320 is 23135004.

It is an interprime number because it is at equal distance from previous prime (400531309) and next prime (400531331).

It is a super-3 number, since 3×400531320³ (a number of 27 digits) contains 333 as substring.

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

It is a junction number, because it is equal to n+sod(n) for n = 400531293 and 400531302.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 76951 + ... + 81990.

It is an arithmetic number, because the mean of its divisors is an integer number (15496845).

Almost surely, 2^400531320 is an apocalyptic number.

400531320 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

400531320 is an abundant number, since it is smaller than the sum of its proper divisors (1087165800).

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

400531320 is a wasteful number, since it uses less digits than its factorization.

400531320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158965 (or 158958 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 18.

The square root of 400531320 is about 20013.2785919749. The cubic root of 400531320 is about 737.1323886587.

Adding to 400531320 its reverse (23135004), we get a palindrome (423666324).

The spelling of 400531320 in words is "four hundred million, five hundred thirty-one thousand, three hundred twenty".