1265556738 has 64 divisors (see below), whose sum is σ = 2804336640. Its totient is φ = 378715392.

The previous prime is 1265556709. The next prime is 1265556739. The reversal of 1265556738 is 8376555621.

1265556738 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (1265556739) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1376643 + ... + 1377561.

It is an arithmetic number, because the mean of its divisors is an integer number (43817760).

Almost surely, 2^1265556738 is an apocalyptic number.

1265556738 is an abundant number, since it is smaller than the sum of its proper divisors (1538779902).

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

1265556738 is a wasteful number, since it uses less digits than its factorization.

1265556738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1551.

The product of its digits is 1512000, while the sum is 48.

The square root of 1265556738 is about 35574.6642710792. The cubic root of 1265556738 is about 1081.6677303014.

The spelling of 1265556738 in words is "one billion, two hundred sixty-five million, five hundred fifty-six thousand, seven hundred thirty-eight".