661014400 has 192 divisors, whose sum is σ = 1792854000. Its totient is φ = 239697920.

The previous prime is 661014373. The next prime is 661014401. The reversal of 661014400 is 4410166.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661014401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1577391 + ... + 1577809.

Almost surely, 2^661014400 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661014400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (896427000).

661014400 is an abundant number, since it is smaller than the sum of its proper divisors (1131839600).

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

661014400 is a wasteful number, since it uses less digits than its factorization.

661014400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 489 (or 472 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 661014400 is about 25710.2003103826. The cubic root of 661014400 is about 871.1045995009.

Adding to 661014400 its reverse (4410166), we get a palindrome (665424566).

The spelling of 661014400 in words is "six hundred sixty-one million, fourteen thousand, four hundred".