20728554 has 32 divisors (see below), whose sum is σ = 51687936. Its totient is φ = 5383920.

The previous prime is 20728549. The next prime is 20728571. The reversal of 20728554 is 45582702.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 21972 + ... + 22895.

It is an arithmetic number, because the mean of its divisors is an integer number (1615248).

Almost surely, 2^20728554 is an apocalyptic number.

20728554 is an abundant number, since it is smaller than the sum of its proper divisors (30959382).

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

20728554 is a wasteful number, since it uses less digits than its factorization.

20728554 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44890.

The product of its (nonzero) digits is 22400, while the sum is 33.

The square root of 20728554 is about 4552.8621766972. The cubic root of 20728554 is about 274.6985302395.

The spelling of 20728554 in words is "twenty million, seven hundred twenty-eight thousand, five hundred fifty-four".