1251264000 has 640 divisors, whose sum is σ = 5106816000. Its totient is φ = 270950400.

The previous prime is 1251263989. The next prime is 1251264017. The reversal of 1251264000 is 4621521.

It is a tau number, because it is divible by the number of its divisors (640).

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 65855991 + ... + 65856009.

It is an arithmetic number, because the mean of its divisors is an integer number (7979400).

Almost surely, 2^1251264000 is an apocalyptic number.

1251264000 is a gapful number since it is divisible by the number (10) 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 1251264000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2553408000).

1251264000 is an abundant number, since it is smaller than the sum of its proper divisors (3855552000).

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

1251264000 is an frugal number, since it uses more digits than its factorization.

1251264000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76 (or 36 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 1251264000 is about 35373.2102020724. The cubic root of 1251264000 is about 1077.5803167575.

Adding to 1251264000 its reverse (4621521), we get a palindrome (1255885521).

The spelling of 1251264000 in words is "one billion, two hundred fifty-one million, two hundred sixty-four thousand".