1265400856 has 8 divisors (see below), whose sum is σ = 2372626620. Its totient is φ = 632700424.

The previous prime is 1265400853. The next prime is 1265400859. The reversal of 1265400856 is 6580045621.

It is an interprime number because it is at equal distance from previous prime (1265400853) and next prime (1265400859).

It is a tau number, because it is divible by the number of its divisors (8).

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1265400853) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 79087546 + ... + 79087561.

Almost surely, 2^1265400856 is an apocalyptic number.

It is an amenable number.

1265400856 is a deficient number, since it is larger than the sum of its proper divisors (1107225764).

1265400856 is a wasteful number, since it uses less digits than its factorization.

1265400856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158175113 (or 158175109 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 37.

The square root of 1265400856 is about 35572.4732904531. The cubic root of 1265400856 is about 1081.6233178444.

The spelling of 1265400856 in words is "one billion, two hundred sixty-five million, four hundred thousand, eight hundred fifty-six".