135821660 has 24 divisors (see below), whose sum is σ = 307166496. Its totient is φ = 50149440.

The previous prime is 135821641. The next prime is 135821689. The reversal of 135821660 is 66128531.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 260936 + ... + 261455.

It is an arithmetic number, because the mean of its divisors is an integer number (12798604).

Almost surely, 2^135821660 is an apocalyptic number.

135821660 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

135821660 is an abundant number, since it is smaller than the sum of its proper divisors (171344836).

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

135821660 is a wasteful number, since it uses less digits than its factorization.

135821660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 522413 (or 522411 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 135821660 is about 11654.2550169455. The cubic root of 135821660 is about 514.0314343345.

The spelling of 135821660 in words is "one hundred thirty-five million, eight hundred twenty-one thousand, six hundred sixty".