20045551 has 8 divisors (see below), whose sum is σ = 21307520. Its totient is φ = 18804312.

The previous prime is 20045549. The next prime is 20045563. The reversal of 20045551 is 15554002.

20045551 = T₈₁₀ + T₈₁₁ + ... + T₈₆₆.

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 20045551 - 2¹ = 20045549 is a prime.

It is a super-2 number, since 2×20045551² = 803648229787202, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20045521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3165 + ... + 7078.

It is an arithmetic number, because the mean of its divisors is an integer number (2663440).

Almost surely, 2^20045551 is an apocalyptic number.

20045551 is a deficient number, since it is larger than the sum of its proper divisors (1261969).

20045551 is a wasteful number, since it uses less digits than its factorization.

20045551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10365.

The product of its (nonzero) digits is 1000, while the sum is 22.

The square root of 20045551 is about 4477.2258151672. The cubic root of 20045551 is about 271.6476794706.

Adding to 20045551 its reverse (15554002), we get a palindrome (35599553).

The spelling of 20045551 in words is "twenty million, forty-five thousand, five hundred fifty-one".