135720820 has 12 divisors (see below), whose sum is σ = 285013764. Its totient is φ = 54288320.

The previous prime is 135720811. The next prime is 135720829. The reversal of 135720820 is 28027531.

It is an interprime number because it is at equal distance from previous prime (135720811) and next prime (135720829).

It can be written as a sum of positive squares in 2 ways, for example, as 108409744 + 27311076 = 10412^2 + 5226^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (135720829) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3393001 + ... + 3393040.

It is an arithmetic number, because the mean of its divisors is an integer number (23751147).

Almost surely, 2^135720820 is an apocalyptic number.

135720820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

135720820 is an abundant number, since it is smaller than the sum of its proper divisors (149292944).

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

135720820 is a wasteful number, since it uses less digits than its factorization.

135720820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6786050 (or 6786048 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 28.

The square root of 135720820 is about 11649.9278967726. The cubic root of 135720820 is about 513.9041896242.

The spelling of 135720820 in words is "one hundred thirty-five million, seven hundred twenty thousand, eight hundred twenty".