1264561440 has 96 divisors (see below), whose sum is σ = 4031487936. Its totient is φ = 333143040.

The previous prime is 1264561433. The next prime is 1264561457. The reversal of 1264561440 is 441654621.

1264561440 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (96).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23970 + ... + 55710.

It is an arithmetic number, because the mean of its divisors is an integer number (41994666).

Almost surely, 2^1264561440 is an apocalyptic number.

1264561440 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 1264561440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2015743968).

1264561440 is an abundant number, since it is smaller than the sum of its proper divisors (2766926496).

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

1264561440 is a wasteful number, since it uses less digits than its factorization.

1264561440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31842 (or 31834 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 33.

The square root of 1264561440 is about 35560.6726595547. The cubic root of 1264561440 is about 1081.3840964808.

The spelling of 1264561440 in words is "one billion, two hundred sixty-four million, five hundred sixty-one thousand, four hundred forty".