20756730 has 16 divisors (see below), whose sum is σ = 49816224. Its totient is φ = 5535120.

The previous prime is 20756719. The next prime is 20756777. The reversal of 20756730 is 3765702.

It is a Harshad number since it is a multiple of its sum of digits (30), and also a Moran number because the ratio is a prime number: 691891 = 20756730 / (2 + 0 + 7 + 5 + 6 + 7 + 3 + 0).

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, 345916 + ... + 345975.

It is an arithmetic number, because the mean of its divisors is an integer number (3113514).

Almost surely, 2^20756730 is an apocalyptic number.

20756730 is an abundant number, since it is smaller than the sum of its proper divisors (29059494).

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

20756730 is a wasteful number, since it uses less digits than its factorization.

20756730 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 691901.

The product of its (nonzero) digits is 8820, while the sum is 30.

The square root of 20756730 is about 4555.9554431535. The cubic root of 20756730 is about 274.8229383631.

The spelling of 20756730 in words is "twenty million, seven hundred fifty-six thousand, seven hundred thirty".