20043215551 has 4 divisors (see below), whose sum is σ = 20086693704. Its totient is φ = 19999737400.

The previous prime is 20043215461. The next prime is 20043215627. The reversal of 20043215551 is 15551234002.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20043215551 - 2⁹ = 20043215039 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20043215651) 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, 21738385 + ... + 21739306.

It is an arithmetic number, because the mean of its divisors is an integer number (5021673426).

Almost surely, 2^20043215551 is an apocalyptic number.

20043215551 is a deficient number, since it is larger than the sum of its proper divisors (43478153).

20043215551 is an equidigital number, since it uses as much as digits as its factorization.

20043215551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43478152.

The product of its (nonzero) digits is 6000, while the sum is 28.

Adding to 20043215551 its reverse (15551234002), we get a palindrome (35594449553).

The spelling of 20043215551 in words is "twenty billion, forty-three million, two hundred fifteen thousand, five hundred fifty-one".