400023720 has 192 divisors, whose sum is σ = 1379851200. Its totient is φ = 100224000.

The previous prime is 400023683. The next prime is 400023737. The reversal of 400023720 is 27320004.

It is a happy number.

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 = 400023693 and 400023702.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1593595 + ... + 1593845.

It is an arithmetic number, because the mean of its divisors is an integer number (7186725).

Almost surely, 2^400023720 is an apocalyptic number.

400023720 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 400023720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (689925600).

400023720 is an abundant number, since it is smaller than the sum of its proper divisors (979827480).

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

400023720 is a wasteful number, since it uses less digits than its factorization.

400023720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 520 (or 513 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 18.

The square root of 400023720 is about 20000.5929912090. The cubic root of 400023720 is about 736.8208636447.

Adding to 400023720 its reverse (27320004), we get a palindrome (427343724).

The spelling of 400023720 in words is "four hundred million, twenty-three thousand, seven hundred twenty".