20556742 has 8 divisors (see below), whose sum is σ = 30858696. Its totient is φ = 10270512.

The previous prime is 20556707. The next prime is 20556743. The reversal of 20556742 is 24765502.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20556743) 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, 213 + ... + 6415.

It is an arithmetic number, because the mean of its divisors is an integer number (3857337).

Almost surely, 2^20556742 is an apocalyptic number.

20556742 is a deficient number, since it is larger than the sum of its proper divisors (10301954).

20556742 is a wasteful number, since it uses less digits than its factorization.

20556742 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7862.

The product of its (nonzero) digits is 16800, while the sum is 31.

The square root of 20556742 is about 4533.9543447194. The cubic root of 20556742 is about 273.9374624178.

The spelling of 20556742 in words is "twenty million, five hundred fifty-six thousand, seven hundred forty-two".