1265617980 has 96 divisors (see below), whose sum is σ = 4295450880. Its totient is φ = 306815040.

The previous prime is 1265617973. The next prime is 1265617981. The reversal of 1265617980 is 897165621.

1265617980 is a `hidden beast` number, since 1 + 2 + 6 + 561 + 7 + 9 + 80 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1265617981) 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, 100594 + ... + 112473.

It is an arithmetic number, because the mean of its divisors is an integer number (44744280).

Almost surely, 2^1265617980 is an apocalyptic number.

1265617980 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1265617980 is an abundant number, since it is smaller than the sum of its proper divisors (3029832900).

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

1265617980 is a wasteful number, since it uses less digits than its factorization.

1265617980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 213096 (or 213088 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 45.

The square root of 1265617980 is about 35575.5250136945. The cubic root of 1265617980 is about 1081.6851778075.

The spelling of 1265617980 in words is "one billion, two hundred sixty-five million, six hundred seventeen thousand, nine hundred eighty".