20628555 has 8 divisors (see below), whose sum is σ = 33005712. Its totient is φ = 11001888.

The previous prime is 20628529. The next prime is 20628557. The reversal of 20628555 is 55582602.

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

It is not a de Polignac number, because 20628555 - 2¹⁰ = 20627531 is a prime.

It is a super-4 number, since 4×20628555⁴ (a number of 30 digits) contains 4444 as substring.

It is not an unprimeable number, because it can be changed into a prime (20628557) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 687604 + ... + 687633.

It is an arithmetic number, because the mean of its divisors is an integer number (4125714).

Almost surely, 2^20628555 is an apocalyptic number.

20628555 is a deficient number, since it is larger than the sum of its proper divisors (12377157).

20628555 is a wasteful number, since it uses less digits than its factorization.

20628555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1375245.

The product of its (nonzero) digits is 24000, while the sum is 33.

The square root of 20628555 is about 4541.8669069007. The cubic root of 20628555 is about 274.2560830698.

The spelling of 20628555 in words is "twenty million, six hundred twenty-eight thousand, five hundred fifty-five".