135291665520 has 480 divisors, whose sum is σ = 509565760704. Its totient is φ = 31883673600.

The previous prime is 135291665507. The next prime is 135291665527. The reversal of 135291665520 is 25566192531.

135291665520 is a `hidden beast` number, since 1 + 3 + 5 + 2 + 91 + 6 + 6 + 552 + 0 = 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 (135291665527) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 121120002 + ... + 121121118.

Almost surely, 2^135291665520 is an apocalyptic number.

135291665520 is a gapful number since it is divisible by the number (10) 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 135291665520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (254782880352).

135291665520 is an abundant number, since it is smaller than the sum of its proper divisors (374274095184).

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

135291665520 is a wasteful number, since it uses less digits than its factorization.

135291665520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1561 (or 1552 counting only the distinct ones).

The product of its (nonzero) digits is 486000, while the sum is 45.

The spelling of 135291665520 in words is "one hundred thirty-five billion, two hundred ninety-one million, six hundred sixty-five thousand, five hundred twenty".