20755720 has 16 divisors (see below), whose sum is σ = 46700460. Its totient is φ = 8302272.

The previous prime is 20755711. The next prime is 20755741. The reversal of 20755720 is 2755702.

It can be written as a sum of positive squares in 2 ways, for example, as 20412324 + 343396 = 4518^2 + 586^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 259407 + ... + 259486.

Almost surely, 2^20755720 is an apocalyptic number.

20755720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20755720 is an abundant number, since it is smaller than the sum of its proper divisors (25944740).

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

20755720 is a wasteful number, since it uses less digits than its factorization.

20755720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 518904 (or 518900 counting only the distinct ones).

The product of its (nonzero) digits is 4900, while the sum is 28.

The square root of 20755720 is about 4555.8445978764. The cubic root of 20755720 is about 274.8184807619.

The spelling of 20755720 in words is "twenty million, seven hundred fifty-five thousand, seven hundred twenty".