1265194656 has 144 divisors (see below), whose sum is σ = 3989932128. Its totient is φ = 377049600.

The previous prime is 1265194631. The next prime is 1265194663. The reversal of 1265194656 is 6564915621.

1265194656 is a `hidden beast` number, since 126 + 519 + 4 + 6 + 5 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 189975 + ... + 196521.

It is an arithmetic number, because the mean of its divisors is an integer number (27707862).

Almost surely, 2^1265194656 is an apocalyptic number.

1265194656 is a gapful number since it is divisible by the number (16) 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 1265194656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1994966064).

1265194656 is an abundant number, since it is smaller than the sum of its proper divisors (2724737472).

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

1265194656 is a wasteful number, since it uses less digits than its factorization.

1265194656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6635 (or 6624 counting only the distinct ones).

The product of its digits is 388800, while the sum is 45.

The square root of 1265194656 is about 35569.5748639199. The cubic root of 1265194656 is about 1081.5645636448.

The spelling of 1265194656 in words is "one billion, two hundred sixty-five million, one hundred ninety-four thousand, six hundred fifty-six".