400642000 has 80 divisors (see below), whose sum is σ = 1056878784. Its totient is φ = 145680000.

The previous prime is 400641973. The next prime is 400642001. The reversal of 400642000 is 246004.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400642001) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12895 + ... + 31105.

Almost surely, 2^400642000 is an apocalyptic number.

400642000 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 400642000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (528439392).

400642000 is an abundant number, since it is smaller than the sum of its proper divisors (656236784).

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

400642000 is a wasteful number, since it uses less digits than its factorization.

400642000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18245 (or 18229 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 400642000 is about 20016.0435651005. The cubic root of 400642000 is about 737.2002803939.

Adding to 400642000 its reverse (246004), we get a palindrome (400888004).

The spelling of 400642000 in words is "four hundred million, six hundred forty-two thousand".