20556737 has 8 divisors (see below), whose sum is σ = 21325440. Its totient is φ = 19792080.

The previous prime is 20556707. The next prime is 20556743. The reversal of 20556737 is 73765502.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20556737 - 2⁶ = 20556673 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20556697 and 20556706.

It is not an unprimeable number, because it can be changed into a prime (20556707) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12662 + ... + 14192.

It is an arithmetic number, because the mean of its divisors is an integer number (2665680).

Almost surely, 2^20556737 is an apocalyptic number.

It is an amenable number.

20556737 is a deficient number, since it is larger than the sum of its proper divisors (768703).

20556737 is a wasteful number, since it uses less digits than its factorization.

20556737 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2023.

The product of its (nonzero) digits is 44100, while the sum is 35.

The square root of 20556737 is about 4533.9537933243. The cubic root of 20556737 is about 273.9374402080.

The spelling of 20556737 in words is "twenty million, five hundred fifty-six thousand, seven hundred thirty-seven".