400003992 has 24 divisors (see below), whose sum is σ = 1083344340. Its totient is φ = 133334640.

The previous prime is 400003987. The next prime is 400003993. The reversal of 400003992 is 299300004.

It is a tau number, because it is divible by the number of its divisors (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400003993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2777734 + ... + 2777877.

Almost surely, 2^400003992 is an apocalyptic number.

It is an amenable number.

400003992 is an abundant number, since it is smaller than the sum of its proper divisors (683340348).

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

400003992 is a wasteful number, since it uses less digits than its factorization.

400003992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5555623 (or 5555616 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 27.

The square root of 400003992 is about 20000.0997997510. The cubic root of 400003992 is about 736.8087508289.

Adding to 400003992 its reverse (299300004), we get a palindrome (699303996).

The spelling of 400003992 in words is "four hundred million, three thousand, nine hundred ninety-two".