631640400 has 60 divisors (see below), whose sum is σ = 2023358592. Its totient is φ = 168437120.

The previous prime is 631640381. The next prime is 631640437. The reversal of 631640400 is 4046136.

It is a tau number, because it is divible by the number of its divisors (60).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 261984 + ... + 264383.

Almost surely, 2^631640400 is an apocalyptic number.

631640400 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

631640400 is an abundant number, since it is smaller than the sum of its proper divisors (1391718192).

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

631640400 is a wasteful number, since it uses less digits than its factorization.

631640400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 526388 (or 526377 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 24.

The square root of 631640400 is about 25132.4571023209. The cubic root of 631640400 is about 858.0052922664.

Adding to 631640400 its reverse (4046136), we get a palindrome (635686536).

The spelling of 631640400 in words is "six hundred thirty-one million, six hundred forty thousand, four hundred".