641552400 has 150 divisors (see below), whose sum is σ = 2302596362. Its totient is φ = 171072000.

The previous prime is 641552381. The next prime is 641552411. The reversal of 641552400 is 4255146.

641552400 is a `hidden beast` number, since 6 + 415 + 5 + 240 + 0 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 11943936 + 629608464 = 3456^2 + 25092^2 .

It is a tau number, because it is divible by the number of its divisors (150).

It is a Harshad number since it is a multiple of its sum of digits (27).

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 29 ways as a sum of consecutive naturals, for example, 22500 + ... + 42300.

Almost surely, 2^641552400 is an apocalyptic number.

641552400 is a gapful number since it is divisible by the number (60) 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 641552400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1151298181).

641552400 is an abundant number, since it is smaller than the sum of its proper divisors (1661043962).

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

641552400 is a wasteful number, since it uses less digits than its factorization.

641552400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19831 (or 19811 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

The square root of 641552400 is about 25328.8846971200. The cubic root of 641552400 is about 862.4700934810.

The spelling of 641552400 in words is "six hundred forty-one million, five hundred fifty-two thousand, four hundred".