20019201551 has 4 divisors (see below), whose sum is σ = 20317995672. Its totient is φ = 19720407432.

The previous prime is 20019201523. The next prime is 20019201563. The reversal of 20019201551 is 15510291002.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15510291002 = 2 ⋅7755145501.

It is a cyclic number.

It is not a de Polignac number, because 20019201551 - 2²² = 20015007247 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20019201551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20019201571) 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 3 ways as a sum of consecutive naturals, for example, 149396960 + ... + 149397093.

It is an arithmetic number, because the mean of its divisors is an integer number (5079498918).

Almost surely, 2^20019201551 is an apocalyptic number.

20019201551 is a deficient number, since it is larger than the sum of its proper divisors (298794121).

20019201551 is an equidigital number, since it uses as much as digits as its factorization.

20019201551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 298794120.

The product of its (nonzero) digits is 900, while the sum is 26.

Adding to 20019201551 its reverse (15510291002), we get a palindrome (35529492553).

The spelling of 20019201551 in words is "twenty billion, nineteen million, two hundred one thousand, five hundred fifty-one".