1265000520 has 64 divisors (see below), whose sum is σ = 4337147520. Its totient is φ = 289142784.

The previous prime is 1265000509. The next prime is 1265000557. The reversal of 1265000520 is 250005621.

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

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, 752137 + ... + 753816.

It is an arithmetic number, because the mean of its divisors is an integer number (67767930).

Almost surely, 2^1265000520 is an apocalyptic number.

1265000520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1265000520 is an abundant number, since it is smaller than the sum of its proper divisors (3072147000).

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

1265000520 is a wasteful number, since it uses less digits than its factorization.

1265000520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1505974 (or 1505970 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 21.

The square root of 1265000520 is about 35566.8457977370. The cubic root of 1265000520 is about 1081.5092411014.

The spelling of 1265000520 in words is "one billion, two hundred sixty-five million, five hundred twenty", and thus it is an aban number.