265740399540 has 576 divisors, whose sum is σ = 1064894100480. Its totient is φ = 54390631680.

The previous prime is 265740399527. The next prime is 265740399541. The reversal of 265740399540 is 45993047562.

265740399540 is a `hidden beast` number, since 2 + 6 + 5 + 7 + 4 + 0 + 3 + 99 + 540 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (265740399541) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 19494207 + ... + 19507833.

It is an arithmetic number, because the mean of its divisors is an integer number (1848774480).

Almost surely, 2^265740399540 is an apocalyptic number.

265740399540 is a gapful number since it is divisible by the number (20) 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 265740399540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (532447050240).

265740399540 is an abundant number, since it is smaller than the sum of its proper divisors (799153700940).

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

265740399540 is a wasteful number, since it uses less digits than its factorization.

265740399540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13737 (or 13722 counting only the distinct ones).

The product of its (nonzero) digits is 8164800, while the sum is 54.

The spelling of 265740399540 in words is "two hundred sixty-five billion, seven hundred forty million, three hundred ninety-nine thousand, five hundred forty".